Intermittent power to AZC

ADAHARSH37

MEMBER
2000 JEEP GRAND CHEROKEE
4.7L
V8
4WD
AUTOMATIC
152,000 MILES

Jeep WJ, at first for two days I had intermittent power to the AZC climate controls. Now nothing. The temperature display does not light up at all and adjusting the mode or speed does nothing. If I hit the rear defrost button I hear a click but that is all. I replaced the blower motor resistor on advice from a friend and still no luck. I have check fuse 20 in the cabin and replaced it along with fuse 7 under the hood. Used a light tester to test my other fuses and everything seems good. Any help is greatly appreciated as it's my only vehicle and it's starting to snow out.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi and thanks for using ECM

If power is good to the AZC module, then you need to check the module itself. It requires a scanner to check and diagnose. I attached two diagnostic flow charts for you to review. If you don't have the right tooling to do it, you may have to consider having it done.

Here is the listing from the bottom of the diagnostic page:

POSSIBLE CAUSES
- Attempt to communicate with the BCM
- Fused (B+) CKT open
- Fused ignition switch output circuit open
- Open PCI bus circuit
- Automatic Zone Control Module

Keep in mind, this type of problem should have set a diagnostic trouble codes related the HVAC system. That would be very helpful, but again, it requires a scanner that can read coding related to it. If you can get those codes, let me know what they are.

Take a look through this and let me know if it helps or if you have questions.

Joe

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