Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Modules connected to the controller area network (CAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. If no communication is detected on the CAN serial data circuit, the DTC is set. A total non-communication condition may be caused by a short to battery or voltage on any of the CAN circuits or a short between the CAN high and low circuits.
The following modules communicate on CAN serial data (LLY engine):
- The engine control module (ECM)
- The transmission control module (TCM)
- The fuel injector control module (FICM)
- The glow plug control module (GPCM)
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.