A/C Signal Circuit Troubleshooting

A/C Signal Circuit Troubleshooting 

1. DTC check

   -1. Turn the vehicle to the ON mode.

   -2. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC

   DTC (PGM-FI)

   Are any Pending or Confirmed DTCs indicated?

   YES 

   Go to the indicated DTCs troubleshooting .

   NO 

   Go to step 2.

2. 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 3.

   NO 

   Do the A/C system test .

3. 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 4.

4. 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 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 5.

5. Open wire check (ACC/A/C MG CLUTCH RLY CL- 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 E (80P)

   -4. Exit the SCS mode with the HDS.

   -5. Turn the vehicle to the ON mode.

   -6. Connect terminals A and B with a jumper wire.

   Terminal A	PCM connector E (80P) No. 31
   Terminal B	Body ground

   Is there a clicking noise from the A/C compressor clutch?

   YES 

   The ACC/A/C MG CLUTCH RLY CL- 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 A/C compressor clutch relay and the PCM. If the connections and terminals are OK, check the A/C compressor clutch relay. If needed, repair an open in the ACC/A/C MG CLUTCH RLY CL- wire between the PCM (E31) and the A/C compressor clutch relay, or other parts in the A/C systems.