TCM Power Relay Sense Circuit Intermittent
The P0892 code indicates an intermittent fault in the transmission control module (TCM) power relay sense circuit. This circuit monitors the voltage supplied to the TCM from the power relay. When the TCM detects an intermittent loss or fluctuation of power, it sets this code. Common causes include a faulty relay, corroded or loose wiring/connectors, a failing TCM, or battery/charging system issues. Intermittent faults can be challenging to diagnose because they may not be present during testing.
01. Most Common Causes
- Faulty TCM power relay
- Corroded or loose wiring/connectors in the relay circuit
- Intermittent short or open in the sense circuit
- Failing TCM
- Weak battery or charging system issues
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Transmission shifting erratically or stuck in gear
- Transmission may go into limp mode
- Intermittent no-start or stalling
- Battery or charging system warning lights
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data to capture conditions when the fault occurred.
Step 2: Inspect the TCM power relay and its socket for corrosion, damage, or loose connections.
Step 3: Check voltage at the TCM power relay sense circuit with a multimeter; look for intermittent drops.
Step 4: Test the relay by swapping with a known good relay and clearing codes to see if the fault returns.
Step 5: Inspect wiring and connectors from the relay to the TCM for breaks, chafing, or corrosion.
Step 6: If no issues found, test the TCM for internal faults; may require professional diagnosis.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The intermittent power loss can cause sudden transmission failure or unsafe driving conditions, such as unexpected gear changes or loss of power.
How much does it cost to fix?▼
Repair costs vary: replacing a relay is $20-$50, wiring repairs $50-$150, and TCM replacement $200-$800. Diagnostic fees add $100-$150.