P1541
DTC P1541: Climate Control Unit Signal Circuit Low Voltage1. Reset the ECM with the HDS.
2. Turn the ignition switch ON (II).
3. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1541 indicated?
YES - Go to step 4;
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the climate control unit and the ECM.
4. Turn the ignition switch OFF.
5. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after it stops.
6. Disconnect the 22P connector from the climate control unit.
7. Disconnect ECM connector C (22P).
8. Check for continuity between ECM connector terminal C5 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (C5) and the climate control unit.
NO - Go to step 9.
9. Substitute a known-good climate control unit and recheck.
10. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1541 indicated?
YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
NO - Replace the original climate control unit.