When you turn the key to start your vehicle, the transmission control module does a self test to see if it can send power to the transmission control relay, which in turn sends power down to the shift solenoids. A sensing circuit between the TCM and the TCR allow for this self test and monitoring of the voltage going to the solenoids. If there is an intermittent problem detected on this circuit, a P0892 DTC will be saved.
How Serious is the Code?
When a P0892 diagnostic trouble code has been saved, the transmission will typically go into Limp Mode to protect itself from damage. This will lock the gearbox into either 2nd or 3rd (or another gear depending on the manufacturer’s TCM programming), which will prevent the normal operation of your vehicle. So yes, this OBD2 code is pretty serious.
Symptoms of a P0892 include:
- Limp mode
- Transmission will not shift
- Connector and/or wiring damage
- Transmission control relay has failed
- ECU or TCM programming problems
How to Diagnose the Code?
Since a P0892 OBDII trouble code relates to battery voltage, the battery should be checked, along with the condition of the terminals. The transmission control relay will need to be tested next. If everything looks good up to this point, then the wiring and connectors, along with any related fuses and fusible links should be checked for signs of damage and short-circuits.
What Repairs Will Fix P0892?
- Repair or replace damaged wiring and/or connectors
- Replace transmission control relay
- Update ECU or TCM software