TCM Power Relay Sense Circuit Intermittent
Your transmission control module isn't reliably sensing power from its relay—like a light switch that keeps flickering on and off. This intermittent connection disrupts the TCM's ability to manage transmission shifting and operation.
The TCM monitors the voltage signal from its power relay feedback circuit to confirm it has stable power supply. The ECM expects a consistent voltage presence when the relay is energized. An intermittent signal—dropping below threshold, then returning—triggers this fault code without a complete loss of power.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| TCM Relay Voltage | 11-14.5V (engine running) | Voltage drops below 9V or becomes intermittent |
| Signal Stability | Continuous steady signal | Intermittent dropout or fluctuation detected |
Code P0892 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0892 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.