Symptoms
Symptoms of a P2769 trouble code may include:
- Malfunction Indicator Lamp (MIL) is illuminated (also known as check engine light)
- Minimal decrease in fuel economy, this will not affect engine performance
Potential Causes
Causes of this DTC may include:
- Damaged transmission wiring harness, loose connection, open or shorted circuit
- Torque Converter Clutch (TCC) solenoid
- Transmission Control Module (TCM)
Diagnostic Steps for P2769 DTC
Wiring Harness – Check that the transmission wiring harness is not damaged or loose. Use a factory wiring diagram to locate the appropriate power source and all connection points between circuits. The transmission may be powered by a fuse or relay and triggered by the TCM. Disconnect the transmission harness at the transmission connector, power source, and TCM. Check continuity within the internal transmission wiring harness by locating the appropriate + and – pins for the torque converter clutch solenoid.
Using a digital volt ohm meter (DVOM) set to ohms scale, check resistance in the circuit with positive and negative leads on the appropriate pins. If resistance is extremely high or above limit (OL), suspect internal harness or TCC solenoid failure – removal of transmission oil pan may be necessary to further diagnose TCC solenoid.
Test wiring between TCM and transmission case wiring harness connector using DVOM set to ohms. Check for possible short to ground by moving DVOM negative lead to a known good ground, resistance should be very high or above (OL).
Torque Converter Clutch (TCC) Solenoid – Check TCC solenoid and internal transmission wiring resistance at transmission case after removing transmission harness plug (if applicable, some makes/models use TCM bolted directly to transmission case). Some makes/models use transmission wiring harness with TCC solenoid and internal harness as one unit. DVOM should be set to ohms scale with positive and negative leads on TCC power and control circuit pins. Resistance should be within manufacturer specifications, if very high or above limit (OL), remove transmission oil pan to inspect solenoid inside transmission if possible. Check voltage on TCC solenoid power circuit or wiring harness connector at TCM with DVOM set to volts scale, positive lead to tested wire and negative to known good ground with vehicle key on/engine off, battery voltage should be present.
Transmission Control Module (TCM) – Since torque converter clutch only engages under certain driving conditions, it will be necessary to monitor TCM with advanced scan tool to determine if TCM is commanding TCC solenoid and what actual feedback reading is to TCM. TCC solenoid is normally controlled by duty cycle for smoother torque converter lockup engagement.
To test if TCM is actually sending signal, graphing multimeter set to duty cycle or digital storage oscilloscope will also be needed. Positive lead is probed into wiring harness plugged into TCM and negative lead to known good ground. Duty cycle should match what TCM is commanding in advanced scan tool reading. If cycle remains at 0% or 100% or is intermittent, recheck connections and if all wiring/solenoid is OK, TCM may be faulty.