A/C Signal Circuit Troubleshooting (2016-18)

DTC check:

- 1. Press the engine start/stop button to select the ON mode.

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

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame

Are any Pending or Confirmed DTCs indicated?

YES

Go to the indicated DTC's troubleshooting.?

Go to step 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.

Do the A/C system test .?

A/C system check:
Check the A/C system .

Does the A/C system operate?

YES

The A/C system circuit is OK.?

NO

Go to step 4.
A/C compressor clutch circuit check:
- 1. Press the engine start/stop button to select the OFF mode.

- 2. Press the engine start/stop button to select the ON mode.

- 3. Activate the A/C CLUTCH in the INSPECTION 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 5.

Open wire check (A/C MG CLUTCH RLY CL- line):

- 1. Press the engine start/stop button to select the OFF mode.

- 2. Jump the SCS line with the HDS, and wait more than 1 minute.

SCS Short

- 3. Disconnect the following connector.

PCM connector A (51P)

- 4. Press the engine start/stop button to select the ON mode.

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

Terminal A	PCM connector A (51P) No. 23
Terminal B	Body ground

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

YES

The A/C MG CLUTCH RLY CL- wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM , then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM .?

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 A/C MG CLUTCH RLY CL- wire between the PCM (A23) and the A/C compressor clutch relay, or other parts in the A/C systems.?