Intermittent start issue and no power to a/c clutch

[peterk9]

No expert here but I would think that the clutch would get the info to turn ON based on the temperature settings.

Peter

 

[BlindViper]

No expert here but I would think that the clutch would get the info to turn ON based on the temperature settings.

Peter

I am not sure but the computer is calling for the compressor to be on.

 

[peterk9]

I am not sure but the computer is calling for the compressor to be on.

That would likely be due to info sent to it from the temperature reading. Perhaps the module or whatever sends the signal to the clutch relay isn't working but I believe you already checked that.

Peter

 

[BlindViper]

That would likely be due to info sent to it from the temperature reading. Perhaps the module or whatever sends the signal to the clutch relay isn't working but I believe you already checked that.

Peter

Ya I was hoping to find out what controls the relay circuit.

 

[ProjectSHO89]

Ya I was hoping to find out what controls the relay circuit.

The PCM does.

Based on the totality of its various inputs and, as long as there are no inhibiting faults, the PCM grounds the "low" side of the A/C clutch relay coil, energizing the relay which sends power from fuse F62 to the clutch relay coil.

 

[BlindViper]

The PCM does.

Based on the totality of its various inputs and, as long as there are no inhibiting faults, the PCM grounds the "low" side of the A/C clutch relay coil, energizing the relay which sends power from fuse F62 to the clutch relay coil.

So if in forscan the pcm is saying the a/c should be on. Then the relay and both fuses are good. What could be the issue?
Yesterday I replaced the transducer sensor. Physically removed the interior fuse panel to check all the fuses. I opened up the engine fuse panel found no issues there. Cleaned all the grounds on the drivers fender. I am at my wits end with this damn car.

 

[ProjectSHO89]

Which specific PID are you looking at in Forscan?

what does Forscan report for both the Evap temperature and the refrigerant pressure values?

Have you scanned both the PCM and the HVAC modules for any DTCs?

 

[BlindViper]

Which specific PID are you looking at in Forscan?

what does Forscan report for both the Evap temperature and the refrigerant pressure values?

Have you scanned both the PCM and the HVAC modules for any DTCs?

 

[BlindViper]

Which specific PID are you looking at in Forscan?

what does Forscan report for both the Evap temperature and the refrigerant pressure values?

Have you scanned both the PCM and the HVAC modules for any DTCs?

In forscan I dont see a test for climate or hvac modules

 

[BlindViper]

Which specific PID are you looking at in Forscan?

what does Forscan report for both the Evap temperature and the refrigerant pressure values?

Have you scanned both the PCM and the HVAC modules for any DTCs?

When running the pcm KOER test I get this.

 

[ProjectSHO89]

The P1464 probably indicates that AC was ON during PCM KOER. Check your procedure for correct diagnostic settings.

 

[BlindViper]

Well, as shown, with the PID CC_AC_SW inactive, the PCM isn't being told to turn on the clutch. Make certain the climate control is set to the A/C mode for this check.

The P1464 probably indicates that AC was ON during PCM KOER. Check your procedure for correct diagnostic settings.

It was definitely on and set to max

 

[ProjectSHO89]

Turn the A/C to OFF for the PCM Quick test. Won't matter for the problem diagnosis, but it prevents a red herring with the P1464 DTC.

Is this a manual or dual automatic climate control?

You may have to step up from the phone app to the Windows-based version of Forscan to run the HVAC module test. It's been awhile since I poked around with it.

 

[BlindViper]

Turn the A/C to OFF for the PCM Quick test. Won't matter for the problem diagnosis, but it prevents a red herring with the P1464 DTC.

Is this a manual or dual automatic climate control?

Dual automatic climate control with the touch screen

 

[ProjectSHO89]

Does the PID ACC_CMD toggle states when the A/C compressor control is switched on/off?

 

[BlindViper]

Does the PID ACC_CMD toggle states when the A/C compressor control is switched on/off?

Yes

 

[ProjectSHO89]

Does the AC Clutch relay respond (click) each time the ACC_CMD toggles state? This may require an assistant to press the button while you use your fingertips to feel the relay for any activity.

If I've correctly traced through your previous posts, you've confirmed that 1) relay pins 2 & 3 are both HOT and that 2) jumpering relay pins 3 & 5 cause the clutch to engage. Are these still correct observations?

 

[BlindViper]

Double post

 

[BlindViper]

Picture is not of the "right" relay. Its just a picture I took to try and getba pin out. Reds are 12v if I jump either to the green the clutch engages. I believe blue is the control from the computer. It was a very low voltage. I did not check I the the relay was clicking with turningthe a/c on/off. I do know the blue voltage was changing while turningon/off. I know that when I snap the relay in place it clicks. Unfortunately I am out of town for work this week. I won't be able to check until Friday.

 

[ProjectSHO89]

Based on what you described, it should be working...

Assuming...if the relay clicks when ACC_CMD changes state, there's nothing wrong with the control circuit. If connecting the "green" terminal of the socket to power engages the clutch, not much left to be a problem except the relay itself or it's socket contacts.