Check electronics limits before you wire the car
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Course: Choose the race class that fits your car and goals
Module: Class your car systematically
Estimated duration: 55 minutes
Electronics are easy to misclassify because they often do not feel like a performance modification from the seat. You bolt in a camera. You add a logger. You route a small harness to a wheel-speed input. You replace a battery and clean up grounds. The car does not gain horsepower, downforce, tire width, or ballast. Yet the rulebook may still care, because electronics can read sensors, communicate with modules, transmit data, change control inputs, or interfere with systems that the class expects to remain stock.
The skill in this lesson is not designing a better data system. That belongs in telemetry-systems-engineering. The skill here is class compliance: you learn to read the electronics section of a class rule so you can say exactly what your logger, camera, wiring, sensors, batteries, software, and wireless links are allowed to do before you install them.
The principle is simple: treat every electronic device as both a part and a path. The part is the physical item: camera, logger, sensor, ECU, battery, harness, switch, antenna, display, or acquisition module. The path is what moves through it: power, ground, sensor signal, bus data, stored files, wireless data, software updates, calibration commands, and driver or crew control. A class rule may permit the part but restrict the path. It may mandate the part but prohibit alternate firmware. It may allow recording but prohibit live transmission. It may allow a camera but prohibit connection to vehicle data. If you only ask whether the box is allowed, you can miss the thing that actually violates the class.
Start with the rulebook definition, not with your mental category. NASA defines telemetry broadly as wireless data communication between vehicle and crew in either direction at any time, including data readable from the ECU or sensors and data usable to modify operating parameters. That definition is important because it makes the boundary about communication and use, not about whether the device feels like a power adder. A logger that records locally may be one compliance question. The same logger streaming values to the crew becomes another. A camera that only stores video may be one question. A camera system that sends live data, reads vehicle sensors, or lets someone outside the car trigger functions becomes a data-path question. The rule decides; your job is to expose the path clearly enough that there is no hidden assumption.
There is also a safety and systems reason to be conservative. Automotive electronic modules depend on correct power supply and earth. A technician text puts the practical rule plainly: complex ECUs still need good power and ground to work. Body control modules and other controllers are built for normal current draws, but overloaded controlled circuits can be damaged. When a sensor circuit fails or sends an invalid value, a computer may set a diagnostic trouble code, substitute a fixed input, infer a value from other sensors, or put part of the system into a fail-safe mode. From a classing standpoint, that matters because a bad electronics install can quietly change what the car is doing while appearing normal to the driver. From a tech-inspection standpoint, it also means the evidence may live in DTCs, module communication errors, software versions, or sensor-calibration status rather than in a visible bracket.
Use a four-map method. Before declaring the car legal, make four maps for every electronics change. The device map names every added, removed, replaced, or reprogrammed electronic item. The data map shows every input, output, storage location, and wireless path. The circuit map shows power, fuse, ground, controlled circuits, bus connections, sensor taps, and connectors. The rule map ties each item and path to the exact rule category: mandated, permitted, unrestricted, restricted, prohibited, or not addressed. If any item lands in not addressed, you do not round it into allowed. You mark it as a question for the steward, tech inspector, series director, or written clarification process.
Read the rule in layers. First, find the definitions section. Definitions are often broader than paddock language. If the rule defines telemetry, acquisition, camera, ECU, sensor, OEM wiring, or data transmission, that definition controls the rest of your reading. Second, find the class-specific allowances. A general rule may permit cameras, while your class may restrict power sources, mounting, wireless use, or sensor inputs. Third, find mandatory equipment language. Mandated hardware can be stricter than optional hardware because the series may be trying to keep every car on the same acquisition package. Fourth, find modification language around wiring, sensors, ECU access, and data buses. A logger is not just a logger if it changes an ECU input, loads a sensor circuit, or adds a communication module. Fifth, find penalty and measurement language. NASA states that a disqualification for vehicle non-compliance or technical infraction means loss of race or qualifying position and related awards or points unless another rule says otherwise. That is a heavy penalty for an invisible wire.
Sub-skill one: classify the electronic object without soft words. Do not write camera and stop. Write forward-facing action camera, powered from internal battery, no vehicle data input, no wireless transmission during session, removable mount. Or write data logger, powered from fused 12-volt source, reads CAN data through diagnostic connector, records to internal memory, Wi-Fi disabled during competition. Or write mandated series logger, supplied harness, part number recorded, software version recorded, wheel-speed sensor input from specified pickup. The more exact description prevents the common paddock dodge where a driver says it is just a camera or just data. The rulebook may not care about your label. It cares about what the object does.
Sub-skill two: trace data from origin to destination. For each value, ask where it originates, where it goes, who can read it, when they can read it, and whether it can change a vehicle operating parameter. Engine speed from the ECU, brake pressure from an added sensor, steering angle from a column sensor, GPS speed inside a camera, accelerometer data from an internal logger, and wheel-speed data from an ABS sensor are different origins. Storage on an SD card, display to the driver, live transmission to the pit, connection to a phone, upload after the session, and remote configuration are different destinations. A compliance review should show whether data stays inside the car during the session or leaves the car while the session is active.
This is where in-motion transmission gets people. The driver often thinks of telemetry as a professional race-engineering setup. Some rulebooks define it much more simply: wireless data between car and crew. That can include data from the ECU or sensors, and it can include data used to change operating parameters. Do not argue from sophistication. Ask whether the device sends data wirelessly, receives data wirelessly, or can be commanded wirelessly. If the answer is yes, find the rule text that allows that exact behavior or disable and document the function.
Sub-skill three: trace power and ground as compliance items. A data device that draws power from the car is now attached to the car's electrical system. You need to know which circuit supplies it, how it is fused, where it grounds, and whether it shares a controlled circuit. Service guidance for body computers warns against grounding or applying voltage to controlled circuits unless service information instructs it, and it calls for high-impedance multimeter testing on electronic circuits. That is not a racing class rule, but it teaches the right compliance habit: never assume a convenient wire is a harmless wire. If you cannot identify the circuit, you cannot confidently say you have not modified a restricted circuit.
The clean compliance question is not only whether the device works. It is whether the installation changes a protected circuit, module, sensor, or harness. A switched 12-volt feed to a fused accessory block may be easy to explain. A splice into a stock sensor reference line is harder. A logger powered from the diagnostic connector may be allowed in one class and prohibited in another. A battery relocation or replacement may be legal under one rule but still create new grounds, straps, or cable paths that affect electronics. Because ECUs and body modules depend on good power and earth, you document battery and ground changes as part of the electronics package, not as a separate reliability chore.
Sub-skill four: identify sensors as rule objects, not just measurements. A sensor is hardware, a circuit, a calibration, and a data source. The ACC diagnostic job sheet in the corpus asks where the sensor is located, whether it is integrated with a module, what other modules use it, which circuits attach to it, what supplies voltage, where the ground is, and when calibration must be performed. That is a useful template for race-car classing. If a class allows data logging but prohibits additional sensors, your brake-pressure transducer is not excused because it only helps you learn. If a class allows a mandated acquisition sensor but not relocation, the mounting location matters. If a class requires stock ABS or EBC components, piggybacking a signal or changing tire size, ride height, or drive ratio may affect system behavior; braking-system guidance specifically notes that electronic brake control systems are affected by vehicle modifications such as tire sizes, curb height, and drive ratios.
Sensor signal type also matters. Brake-system material distinguishes passive variable-reluctance sensors that create analog AC sine waves from active magneto-resistive and Hall-effect sensors that create digital square-wave signals. You do not need to become the electronics engineer for this lesson, but you do need to respect that a sensor tap is not automatically neutral. Loading, grounding, or sharing the wrong signal can create DTCs, degrade signal quality, or change what another module sees. If the rule protects OEM sensors or requires a stock harness, you treat the sensor circuit as part of the restricted system.
Sub-skill five: separate recording, display, telemetry, and control. Recording means the device stores information for later review. Display means the driver can see information in the car. Telemetry means data is communicated wirelessly between vehicle and crew under the governing definition. Control means data or commands can modify operating parameters. A single product can do all four. Your compliance note should not say data logger allowed unless you have checked which functions are allowed. It should say local recording allowed under the rule, driver display permitted or disabled, wireless transmission prohibited and disabled, remote configuration disabled, ECU-write capability absent or locked, with evidence attached.
This distinction is especially important for cameras. The bonded corpus does not provide camera-specific club-racing rules, so do not invent a camera allowance. Apply the same boundary method. A simple self-contained camera may be only a recording and mounting question. A camera that overlays GPS speed, reads ECU data, connects to a phone, streams video, or receives remote commands touches data, wireless transmission, or control questions. The safe compliance move is to state each function separately. If the rule only says cameras are allowed, that may not automatically allow every data and wireless feature packaged inside a modern camera system.
Sub-skill six: treat software and firmware as parts of the car. The body-computer job sheet asks a technician to record BCM part number, software version, and hardware version with a scan tool. The flashing procedure asks the technician to enter a part number or VIN, select a flash file, complete the transfer, cycle ignition as instructed, and erase DTCs that may have been set during the process. For racing compliance, that tells you what evidence matters when a class mandates an ECU, acquisition box, or body module. A box with the right label but the wrong software may not be the same legal part. A legal logger with an unauthorized firmware feature can become a problem if that feature enables live transmission, extra channels, or parameter changes. When the rule mandates acquisition hardware, capture the part number, serial number if available, hardware version, software version, flash file or firmware version, and any configuration file that controls channels or transmission.
Software can also be a powertrain modifier, but do not duplicate the sibling lesson on powertrain changes here. The electronics question is narrower: does this software or configuration change move the car outside the allowed electronics boundary? If the file only sets logger sample rate, channel names, or storage format, classify that. If it can write ECU parameters, change ignition, alter throttle, control boost, disable a module, or change an operating mode, stop and read the powertrain and electronics rules together.
Sub-skill seven: close the loop with diagnostics and evidence. A compliant install should leave a trail that another competent person can inspect. The job sheets in the corpus repeatedly use wiring diagrams, scan tools, DMMs, lab scopes, DTC retrieval, module-communication checks, voltage measurements, ground tests, activation tests, and calibration procedures. You do not need every tool for every club install, but you do need a habit: after the electronics change, prove that the car still communicates normally, that no relevant DTCs remain, that the supply and ground are sane, and that any sensor requiring alignment or calibration has been handled according to service information. If a scan tool reports hard or intermittent codes after the install, that is not just a repair concern. It is evidence that your electronics change may have disturbed a system the class assumes remains stock.
Worked example: NASA telemetry boundary. Suppose you install a logger that records ECU RPM, throttle position, GPS speed, and brake pressure. If it records locally and you download after the session, your first compliance question is whether the class allows those channels and those sensors. If it sends live values to a crew member during the session, the telemetry rule is triggered because the data is wirelessly communicated between vehicle and crew. If the crew can send a command back that modifies an operating parameter, the risk is even higher because the definition includes data used to modify operating parameters. The correct answer is not to call it advanced data or harmless coaching. The correct answer is to mark every in-session wireless path and match it to a written allowance.
Worked example: the disconnected ground strap after body work. The corpus describes a case where a vehicle developed intermittent electrical problems after body work, with DTCs across multiple modules. The technician traced the issue to a disconnected ground strap between the bulkhead and hood. The strap suppressed EMI from sheet metal behaving like a capacitor, and the missing ground created interference with nearby computer-controlled circuits. In classing terms, this is the warning shot. A body repair, camera mount, battery change, or harness reroute can create an electronics problem without looking like a performance modification. If your class restricts wiring or electronic systems, your compliance check must include grounds, straps, routing, and interference risk, especially after bodywork or fabrication.
Worked example: electronic brake control and tire or driveline changes. A sibling lesson covers tire, wheel, aero, and ballast limits. Your electronics cross-check is that electronic brake control systems can be affected by tire size, curb height, and drive ratios. If your class permits a tire change but requires stock ABS, traction control, or stability behavior, do not assume the electronics are unaffected. The tire rule may say one thing and the electronics rule may say another. Your job is to identify whether a changed rolling radius, ride height, or drive ratio changes the sensor information an electronic brake system uses, then ask whether the class treats that as allowed, tolerated, or prohibited.
Worked example: mandated acquisition hardware. A series may require a specific acquisition box so officials can collect uniform data or police a class. Treat that box like a controlled module. Record its part number, hardware version, software version, wiring harness, sensor list, and any required calibration. Do not add a parallel sensor, alternate ground, extra wireless bridge, or firmware update because it is convenient. If the official hardware has a prescribed harness, use that harness unless a written rule permits changes. If it requires a calibration procedure, perform and document it. The compliance point is not that the logger works; it is that it remains the mandated logger in the mandated configuration.
Worked example: a sensor added for learning. You want brake-pressure data because it helps you understand trail braking. That is a reasonable learning goal, but classing asks a different question. Where is the pressure sensor installed? Does it open the brake hydraulic system? Is it an added sensor in a class that prohibits added sensors? Is it powered from a restricted circuit? Does it share ground or reference voltage with an OEM module? Does it transmit live data? If the rule allows local data acquisition with added sensors, document the allowance. If the rule only allows cameras or only allows the mandated logger, the educational value of the channel does not make it legal.
Drill: the three-pass electronics compliance walkdown. Do this before your next event or before you buy the device. Pass one is the device inventory, 15 minutes. List every electronic item that is added, removed, replaced, reprogrammed, powered, mounted, or connected for the event. Include cameras, loggers, displays, phone mounts with data functions, sensors, antennas, switches, batteries, chargers, acquisition modules, and harness changes. Pass two is the data-path trace, 20 minutes. For each item, write data in, data out, storage, display, wireless send, wireless receive, ECU or sensor access, and whether it can modify operating parameters. Pass three is the circuit and rule trace, 25 minutes. For each item, write power source, fuse, ground, vehicle circuit, module or sensor connection, rule paragraph, status, and open questions.
The success criterion is a one-page electronics map with zero mystery paths. You are successful when a tech inspector, instructor, or crew chief can point to any wire or wireless function and you can say what it does, where it gets power, where it gets data, whether it transmits, what rule allows it, and what evidence proves the configuration. If you cannot answer those questions, the drill did its job. The point is to find the gray area at your workbench, not in impound.
Calibration cues. Your electronics review is improving when your notes change from product names to functions. Instead of AIM logger, GoPro, or battery, your map says local logger reading CAN and brake pressure with Wi-Fi disabled, self-contained camera with no vehicle data connection, or battery replacement with unchanged ground architecture. You are improving when you can distinguish a legal recording function from a prohibited live-transmission function without relying on brand reputation. You are improving when you can identify the exact sensor circuits you touched, the ground point you used, and the module communication state after the install.
A strong compliance packet has three signatures. First, it is specific: part numbers, software versions, harness routing, sensor locations, power and ground points, and wireless settings are written down. Second, it is testable: DTCs are checked, communication errors are resolved, calibration requirements are documented, and the system still behaves normally. Third, it is humble: anything not plainly allowed is listed as an open question, not hidden behind a casual label.
Failure mode: the silent transmitter. The device records fine, the driver never looks at live data, and nobody calls it telemetry. But the unit creates a Wi-Fi, Bluetooth, cellular, or other wireless data path during the session. Under a broad telemetry definition, the existence and use of wireless communication may matter even if the driver did not think of it as a pro-level telemetry system. Recovery is straightforward: identify the wireless path, disable it if the rule requires, document the setting, and get a written answer if the rule is ambiguous.
Failure mode: the harmless sensor tap. You tap a stock sensor because you only want a copy of the signal. The car runs, so you assume the tap is harmless. The electronics texts push against that assumption. Controlled circuits can be damaged by inappropriate voltage or grounding, electronic tests require high-impedance tools, and sensor circuits may be checked for reference voltage, signal quality, and ground. The classing recovery is to treat the tap as a modification until proven allowed. Use the wiring diagram, identify the circuit, verify you are not loading or altering the signal, and match the tap to a rule allowance.
Failure mode: the mandated box with private changes. The series requires a logger, but you update firmware, change the harness, add channels, or bridge it to another device. The box is still physically present, yet its configuration may no longer match the mandate. Recovery is to return to the required hardware, firmware, harness, channels, and calibration, then document the version information just as a technician records module part, hardware, and software information.
Failure mode: the electrical repair that becomes a class problem. A ground strap is left off, a harness is rerouted near sheet metal, a battery ground is changed, or a camera power lead is tied into a controlled circuit. The car may show intermittent DTCs or communication faults rather than a clean failure. Recovery is to stop treating electronics as accessories and inspect the basic electrical architecture: power supply, earth, circuit protection, grounds, straps, routing, and module communication. If the install disturbed a restricted system, repair the system before you argue legality.
Failure mode: the camera exception that swallows the data rule. Some drivers read a camera allowance and assume it permits every feature in a modern camera package. That is weak reading. The camera may be allowed as a video recorder while its data overlay, live stream, phone link, GPS channel, sensor connection, or remote control function is still governed by data, telemetry, or wiring rules. Recovery is to split the camera into functions and classify each one separately.
Common mistakes. Mistake one is performance-only thinking. Bad version: if it does not make the car faster, it must be legal. Good version: if it changes electronics, reads a sensor, transmits data, modifies software, or touches a protected circuit, it gets a rule trace.
Mistake two is product-name compliance. Bad version: the rule allows cameras, so this whole camera ecosystem is allowed. Good version: the camera body, mount, power, vehicle-data input, GPS overlay, wireless function, and remote control function are each classified.
Mistake three is ignoring direction. Bad version: telemetry only means data from the car to the pit. Good version: check both directions. The NASA definition includes wireless communication in either direction, and it also cares about data usable to modify vehicle operating parameters.
Mistake four is treating software as invisible. Bad version: the hardware is stock, so the electronics are stock. Good version: record hardware version, software version, firmware, flash file, and configuration because software can change what the hardware is.
Mistake five is trusting a clean dashboard. Bad version: no warning light means no electronics issue. Good version: after an install, scan for DTCs and module communication errors, because some faults are stored, intermittent, or handled by fail-safe logic.
Mistake six is leaving grounds out of the rule packet. Bad version: grounds are just workmanship. Good version: grounds, straps, routing, and power supply are part of the electronics installation because modules rely on them and interference can disturb computer-controlled circuits.
Mistake seven is asking tech too late. Bad version: install first, hope the inspector agrees. Good version: make the four maps first, mark open questions, and ask for clarification before the car is committed to a class or event.
When this principle breaks down, it usually breaks because the corpus of rules is too thin, not because the method is wrong. If a class rule says data systems are unrestricted except for live telemetry, you still need to know what the rule means by telemetry. If a rule says only series-mandated acquisition is allowed, you still need to know whether a camera with no vehicle data counts separately. If a rule is silent on phones, wireless cameras, or diagnostic ports, silence is not permission. The correct move is not to invent an allowance. The correct move is to document the exact function and ask the official authority.
Cross-reference the sibling lessons, but keep this boundary clean. Base eligibility tells you whether the car can enter the class at all. Powertrain-modifier tracing tells you whether ECU tunes, engine control, or drivetrain electronics change performance classification. Tire, wheel, aero, and ballast lessons cover visible hardware limits, while this lesson catches electronic consequences such as sensor behavior and data systems. Class bump versus ineligibility handles what happens when the rule gives a migration path or a hard stop. Telemetry-systems-engineering teaches how to design and analyze the system once you already know it is legal.
The habit to keep is this: never let an electronic device stay generic. Name the box, name the path, name the circuit, name the software, name the rule. Electronics only stay quiet when nobody asks what they are doing.
Worked example: NASA telemetry boundary
Suppose you install a logger that records ECU RPM, throttle position, GPS speed, and brake pressure. If it records locally and you download after the session, your first compliance question is whether the class allows those channels and those sensors. If it sends live values to a crew member during the session, the telemetry rule is triggered because the data is wirelessly communicated between vehicle and crew. If the crew can send a command back that modifies an operating parameter, the risk is higher because the definition reaches data used to modify operating parameters. The correct answer is to mark every in-session wireless path and match it to a written allowance.
Worked example: disconnected ground strap after body work
The corpus describes a vehicle with intermittent electrical problems after body work and DTCs across multiple modules. The technician traced the issue to a disconnected ground strap between the bulkhead and hood. For classing, the lesson is that bodywork, battery work, camera mounting, and harness routing can create electronics issues without looking like performance modifications. A compliance check should include grounds, straps, routing, and interference risk whenever an electronics device or wiring change is added.
Worked example: mandated acquisition hardware
A series-mandated logger should be treated like a controlled module, not like a generic accessory. Record part number, hardware version, software version, harness, sensor list, and calibration status. If the mandate implies a specific harness or firmware, do not add a parallel sensor, alternate ground, wireless bridge, or firmware update unless written rules permit it. The compliance point is not merely that the logger works. The point is that it remains the required acquisition system in the required configuration.
Common mistakes
The biggest mistake is performance-only thinking: if it does not add speed, the driver assumes it is legal. Good compliance asks whether the device reads a sensor, changes software, touches a protected circuit, or transmits data. Product-name compliance is another trap: a camera allowance does not automatically allow every data overlay, phone link, live stream, or remote-control function bundled with the camera. A third error is treating software as invisible. Hardware version, software version, firmware, flash file, and configuration can matter because software can change what hardware does. A fourth error is trusting a clean dashboard instead of scanning for DTCs and communication faults after the install.
Drill: three-pass electronics compliance walkdown
Before the next event, run a three-pass walkdown. Pass one is a 15-minute device inventory of every electronic item added, removed, replaced, powered, mounted, or programmed. Pass two is a 20-minute data-path trace for each item: data in, data out, storage, display, wireless send, wireless receive, ECU or sensor access, and whether it can modify operating parameters. Pass three is a 25-minute circuit and rule trace: power source, fuse, ground, vehicle circuit, module or sensor connection, rule paragraph, compliance status, and open questions. Success means you have a one-page map with zero mystery paths and no unclassified wireless functions.
When this principle breaks down
This method breaks down only when the rule text is too thin to answer the actual function in the car. Silence is not a safe allowance. If the rule does not clearly address a phone-linked camera, a diagnostic-port logger, a wireless bridge, or a mandated box with different firmware, document the exact function and ask the official authority before installing or declaring the car. Refuse to round an unknown electronics path into allowed just because the device seems harmless from the driver's seat.
Author Review
No quiz questions are attached to this lesson.
Sources
| # | Document | Chunk | Pages | Score | Collection |
|---|---|---|---|---|---|
| 1 | NASARules2023 | 62391102bb81302775622783501e43f8 | 112 | 1 | uio_books_raw_v1 |
| 2 | Todays Technician Automotive Electricity and Electronics, Classroom and Shop Manual Pack, Spiral bound Version (Barry Hollembeak) | a5df81d031dc36353f0583dd4c407866 | 962 | 1 | uio_books_raw_v1 |
| 3 | Todays Technician Automotive Electricity and Electronics, Classroom and Shop Manual Pack, Spiral bound Version (Barry Hollembeak) | d970d97d6523904b5c3b933f3bf0fbe4 | 981 | 1 | uio_books_raw_v1 |
| 4 | Automotive Braking Systems Goodnight | 824efbcb-fea9-be12-876c-93cf090a7134 | 300 | 1 | uio_books_raw_v1 |
| 5 | Todays Technician Automotive Electricity and Electronics, Classroom and Shop Manual Pack, Spiral bound Version (Barry Hollembeak) | 8a14874c2dd1a52d549255310a7bd6b5 | 1306 | 1 | uio_books_raw_v1 |
| 6 | Todays Technician Automotive Electricity and Electronics, Classroom and Shop Manual Pack, Spiral bound Version (Barry Hollembeak) | f25d38f4dde3852f2a742aef028032c5 | 990 | 1 | uio_books_raw_v1 |
| 7 | Advanced Automotive Fault Diagnosis. Automotive Technology. Vehicle Maintenance and Repair Tom Denton | dc665b64-0d04-8615-5660-b67594d726b5 | 261 | 1 | uio_books_raw_v1 |
| 8 | Todays Technician Automotive Electricity and Electronics, Classroom and Shop Manual Pack, Spiral bound Version (Barry Hollembeak) | 9ce62eb84a83259e20a9d00267b304c2 | 1219 | 1 | uio_books_raw_v1 |
| 9 | Todays Technician Automotive Electricity and Electronics, Classroom and Shop Manual Pack, Spiral bound Version (Barry Hollembeak) | 54f154b48bb8bbfa8d47cd1665b924d0 | 1174 | 1 | uio_books_raw_v1 |
| 10 | Todays Technician Automotive Electricity and Electronics, Classroom and Shop Manual Pack, Spiral bound Version (Barry Hollembeak) | 4224370c5a49d50926a369e788cc6213 | 1342 | 1 | uio_books_raw_v1 |
| 11 | Todays technician classroom manual for automotive brake systems (Ken Pickerill Ken Pickerill) | 7389bc96c7ee8afaef9141b6fc34235b | 427 | 1 | uio_books_raw_v1 |
| 12 | Advanced Automotive Fault Diagnosis. Automotive Technology. Vehicle Maintenance and Repair Tom Denton | 038ef746-288d-7582-811d-fe89b4d16f73 | 158 | 1 | uio_books_raw_v1 |
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| 14 | Engine Testing Theory and Practice (Plint, Martyr) | 85db5d1a41ae35b0701b3d81be0e0597 | 230 | 1 | uio_books_raw_v1 |