Common Symptoms
- Check Engine Light or transmission warning light illuminated
- Transmission stuck in one gear or limp mode
- Harsh or erratic shifting
- No upshift or downshift response
- Intermittent loss of transmission function
Most Likely Root Causes
- Faulty transmission control module (TCM)
- Damaged wiring harness between TCM and transmission
- Corroded or loose connector at TCM or transmission
- Low battery voltage or charging system issues
- Failed transmission range sensor or solenoid
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Component Location
Transmission control module is typically mounted on or near the transmission case, or under the center console near the shifter assembly.
Manufacturer Notes
This code indicates a general electrical malfunction in the transmission control system and often requires further diagnosis to identify the specific circuit fault.
Also diagnosing J1939 SPN/FMI codes?
Heavy-duty trucks often throw both OBD-II and J1939 faults simultaneously. AI Diesel Tech handles both protocols in a single guided session.
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