The P0927 error code indicates that the Engine Control Module (ECM) has detected a problem in the operation of the transmission gear shift reverse actuator. The gear shift reverse actuator controls how a vehicle’s transmission shifts into reverse.
What does the P0927 code mean?
In simple terms, the OBD-II fault code P0927 means that the ECM has found a signal indicating that the voltage in the gear shift reverse actuator was above normal parameters.
This voltage anomaly can be caused by a malfunction of the guide rail or the shift shaft corresponding to reverse gear in the transmission, making it difficult or impossible to shift into reverse.
What causes the P0927 code?
Although several issues can trigger a higher-than-normal reading in the reverse actuator circuit, causing the Check Engine light to illuminate on a vehicle’s dashboard, the cause of the code is likely due to a mechanical problem in the transmission.
What are the symptoms of the P0927 code?
- When the P0927 code causes the Check Engine light to come on, the following symptoms may be present:
- Difficulty or inability to shift into reverse
- Reduced energy efficiency
How does a mechanic diagnose the P0927 code?
A certified technician must first verify the existence of the P0927 code with a specialized scan tool before proceeding further. Several scans may be necessary to determine if the problem is intermittent or constant, along with other tests, including a visual inspection.
Common mistakes when diagnosing the P0927 code
After recording the P0927 code, a technician may make the following errors:
Not checking that the voltage through the gear shift reverse actuator is high
Failing to visually inspect the transmission, especially components related to reverse gear
Forgetting to clear the OBD-II P0927 error code once the problem is resolved
How severe is the P0927 code?
A vehicle registering the P0927 code may still be drivable, although it may not shift into reverse easily or at all. Over time, this issue can affect the operation of other parts and systems, so it is advisable to promptly contact a qualified mechanic for assistance in diagnosing and repairing the root cause of the P0927 code being recorded.
What repairs can fix the P0927 code?
- After a qualified mechanic has used a specialized scan tool to verify the existence of the P0927 code, the vehicle may need the following repairs:
- Adjustment of the guide rail or shift shaft corresponding to reverse gear
- Replacement of the entire transmission
- Replacement of the ECM in rare cases