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.
DTC P1698: No Bus Message From Trans Control Module: Description
Messages from Transmission Control Module (TCM) are monitored when engine is running, transaxle in Drive and battery voltage more than 10 volts. DTC will set in PCM memory if no bus messages are received from TCM for 10 seconds. Possible causes for DTC to set are: defective PCM, or defective connectors or wiring.
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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.
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