A/C Signal Circuit Troubleshooting
- A/C compressor clutch condition check
-1. Start the engine, and let it idle.
-2. Turn the blower switch on.
-3. Turn the A/C switch on.
-4. Check the parameter(s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit A/C CLUTCH ON Do the current condition(s) match the threshold?
YES
Go to step 2.
NO
- A/C system check
-1. Check the A/C system .
Does the A/C system operate?
YES
The A/C system circuit is OK.
NO
Go to step 3.
- A/C compressor clutch circuit check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Turn the vehicle to the ON mode.
-3. Activate the A/C CLUTCH in the Function Test Menu with the HDS.
A/C CLUTCH
Is there a clicking noise from the A/C compressor clutch?
YES
The A/C compressor clutch circuit is OK. Do the A/C system test .
NO
Go to step 4.
- Open wire check (ACCL line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Jump the SCS line with the HDS, and wait more than 1 minute.
-3. Disconnect the following connector.
PCM connector A (50P) -4. Turn the vehicle to the ON mode.
-5. Connect terminals A and B with a jumper wire.
Terminal A PCM connector A (50P) No. 28 Terminal B Body ground Is there a clicking noise from the A/C compressor clutch?
YES
The ACCL wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If the symptom/indication goes away and the PCM was substituted, replace the original PCM .
NO
Check for poor connections or loose terminals at the power distribution module (A/C compressor clutch relay circuit) and the PCM. If the connections and terminals are OK, check the power distribution module. If needed, repair an open in the ACCL wire between the PCM (A28) and the power distribution module, or other parts in the A/C systems.