A/C Signal Circuit Troubleshooting
A/C Signal Circuit Troubleshooting1. 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 indicated ON?
YES - Go to step 5.
NO - Do the A/C system test.
5. Check the A/C system.
Does the A/C system operate?
YES - The air conditioning system circuit is OK.
NO - Go to step 6.
6. Turn the ignition switch OFF.
7. Turn the ignition switch ON (II).
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.
NO - Go to step 9.
9. Momentarily connect under-hood fuse/relay box 14P connector terminal No. 10 to body ground with a jumper wire several times.
Is there a clicking noise from the A/C compressor clutch?
YES - Repair open in the wire between the ECM/PCM (E18) and the A/C clutch relay.
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.