98 GTP - HVAC Question

eippermx · 10-21-2007, 03:20 PM

When I set the heat setting to 90 degrees, cold air blows out of the LH panel while barely warm air blows out on the RH side. The HVAC control CJ2 reports both 105 & 106 DTCs -- shorted/open LH/RH actuators. I checked the DIC/HVAC fuse and it's good. I'm wondering if I am looking at the CJ2 being defective vice both actuators being bad. Any thoughts?

BNaylor · 10-21-2007, 03:55 PM

Maintenance man icon waving at you?

Can't beat the CJ2 diagnostics capability. It could be the head unit or even both actuators. Easy enough. I'd go for the right (passenger side) actuator since it is easier to access although still a PITA.

Pull the temp actuator electrical connector and look for the 4-5 volts that comes from the climate control head unit. If missing it is the head unit, otherwise one or both actuators.

If you need the GM FSM auto climate control system (ACC) diagnostics I have it on PDF file.

eippermx · 10-21-2007, 04:15 PM

Quote:

Originally Posted by BNaylor

Maintenance man icon waving at you?

Can't beat the CJ2 diagnostics capability. It could be the head unit or even both actuators. Easy enough. I'd go for the right (passenger side) actuator since it is easier to access although still a PITA.

Pull the temp actuator electrical connector and look for the 4-5 volts that comes from the climate control head unit.

BWA-HAHAHAHAHA You busted me, Bob!

:

I discovered the PITA situation and weussed out.

eippermx · 10-21-2007, 06:22 PM

Bob,
Couldn't find the RH actuator. I have a funny feeling it was right in front of me. Found the LH (driver) actuator easily. Oi Vey getting to it was a bit of a PITA. Modified my probe so I could measure the slim 10 pin connector. Pin measurements: 5 = 13.9 vdc, 6 = 5 vdc, 7= 0 vdc, 8= 0 vdc, 9 = 4.97 vdc 10 = 5 vdc. Pin 7 is the sensor ground. Not too sure how to test that pin.

buckeye1872 · 10-21-2007, 09:57 PM

dont know if its the same as my 2000GTP, but I can clearly see my pass side actuator by dropping out glove box.

BNaylor · 10-22-2007, 09:46 AM

Quote:

Originally Posted by buckeye1872

dont know if its the same as my 2000GTP, but I can clearly see my pass side actuator by dropping out glove box.

That is correct on all '97-'03 models with dual zone climate control.

Eippermx just send me a PM with your regular email address and I'll send you the auto HVAC PDF file.

eippermx · 10-28-2007, 07:41 PM

I've finally have a handle on my no heat on the left air panel problem. The left-hand actuator is not functioning. With the glove compartment door removed (see this thread why I started on the right) I was able to easily get to the right-hand actuator and remove its electrical connector. Pins 5,7, 9 & 10 checked out per the specs. I checked pin 7 by back-probing the connector to pin 5. Pin 5 has battery voltage originating from the fuse.
I then had a funny feeling that even though the CJ2 diagnostics indicated the actuator was bad on the right-hand side -- I decided to play with the temperature control knob. I went from 60 to 90 degrees and nothing happened. DOH! I remembered that I needed to press the dual climate button in order to switch to the passenger side of the control and VOILA'! The right-hand actuator started working. Then re-verified the electrical wiring to the left-hand actuator and then thought of a simpler test for the left-hand actuator. I switched to the driver side control using the dual button.
On my back partially under the dash, I put my finger on the the end of the actuator tine. It has a slot on the end of it so it's easy to tell when it moves. Then I move my hand to the climate control knob and moved it from 60 to 90 degrees. I checked the position of the slot on the actuator and found it didn't move. I moved the temperature control knob back and a forth a few more times to verify the actuator didn't move the flap. Now, I need to price out a new left-hand actuator and procure it.
Thanks once again to Bob for helping troubleshoot this problem.

richtazz · 10-29-2007, 03:14 PM

The AC-Delco part number for your actuator is 15-72971 (GM #89018365).

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