A/C Signal Circuit Troubleshooting
A/C Signal Circuit Troubleshooting
1.
DTC check:

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
     


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:

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
     
     
     
3.
A/C system check:

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:

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 INSPECTION MENU with the HDS.

  

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):

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.?