TL FWD V6-3.5L (2009)
A/C Signal: Testing and Inspection
A/C Signal Circuit Troubleshooting
1. Start the engine.
2. Turn the blower switch on.
3. Turn the A/C switch on.
4. Check the A/C CLUTCH in the DATA LIST with the HDS.
Does it indicate ON?
YES - Go to step 5.
NO - Check the A/C system. See: Heating and Air Conditioning/Testing and Inspection/Component Tests and General Diagnostics/A/C
System Inspection
5. Check the A/C system operation.
Does the A/C system operate?
YES - The air conditioning system circuit is OK.
NO - Go to step 6.
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
7. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
8. Activate the A/C CLUTCH in the INSPECTION MENU with the HDS.
Is there a clicking noise from the A/C compressor clutch?
YES - Do the A/C system test. See: Heating and Air Conditioning/Testing and Inspection/Component Tests and General Diagnostics/A/C
System Test
NO - Go to step 9.
9. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
10. Jump the SCS line with the HDS.
11. Disconnect PCM connector A (49P).
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
13. Momentarily connect PCM connector terminal A13 to body ground with a jumper wire several times.
Is there a clicking noise from the A/C compressor clutch?
YES - Update the PCM if it does not have the latest software, See: Testing and Inspection/Programming and Relearning/PCM Update or
substitute a known-good PCM, See: Testing and Inspection/Initial Inspection and Diagnostic Overview then recheck. If the
symptom/indication goes away with a known-good PCM, replace the original PCM. See: Engine Control Module/Service and Repair/PCM
Replacement
NO - Check for poor connections or loose terminals at the A/C clutch relay and the PCM. If the connections are OK, check the A/C clutch
relay. See: Power and Ground Distribution/Testing and Inspection If needed, repair open in the wire between the PCM (A13), the A/C clutch
relay, and the other A/C system parts.
