GMT900 Platform (2008 Escalade) Rear Lift-gate Glass and Rear Wiper Inop

pdosescu · January 7, 2019

Good afternoon everyone,

I am hoping to get some help in diagnosing an issue with my 2008 Cadillac Escalade. The rear lift-gate window is inoperable from both the exterior button on the lift-gate and the key fob. In addition, the rear wiper is also inoperable. I believe these two to be linked. Here are the details:

Vehicle: 2008 Cadillac Escalade (short) AWD Luxury

Complaint: Rear lift-gate window and rear wiper inoperable. Nothing happens when wiper is activated. Lights flash, relay clicks when the key fob button for the glass is pressed.

What I've done so far:

1) Verified rear wiper fuse in good working order

2) Verified all other fuses related to rear lift-gate in good working order

3) Verified power to the fuse panel for respective fuses

4) Scanned for faults and pulled DTC B3265-00 Trunk/Hatch/LIftglass Release Output Circuit

5) De-trimmed rear, inspected wiring harness at body-gate connection. Found no damaged wiring

6) Removed harness connector before the lift-gate and tested wiring for continuity going to wiper motor and glass latch. Found no breaks in wiring

7) Pulled harness off latch and tested the harness, found 2/4 wires to have constant power, other 2 do not. I then educated myself on how the latch works in relation to the BCM.

8) Ran jumper wire and verified latch will pop when it receives a signal.

9) Tested resistance in ohms of the latch in the vehicles compared to a new latch (factory part). Found similar results

10) De-trimmed along the door sills and inspected wiring for crimped sections or any other damages, found none.

11) Tested the latch closure sensor and found it operational, opening and closing the circuit.

12) Tested new latch and found still not operational. Tested wipers, still not operations

13) Measured voltage on wiper motor harness. Found proper voltage.

14) Pulled key fob antenna module, inspected wiring, found no damage or corroded connectors

15) Inspected wiring along roof line behind headliner where main harness runs, no frayed wiring or anything like that

16) Replace exterior button due to age and brittleness of the touch-pad. No change, still nonoperational. Factory part.

I pulled the diagram and it shows there is a Tailgate Release Relay (KR95A) but I don't know where it is located. According to AllData, it's behind the glove box. Can anyone confirm this? I hear a click behind there. My next step is taking out the blower motor and testing that relay for resistance between pins. Besides that, I have to suspect a bad BCM.

Does anyone have any other ideas or suggestions?

THANK YOU in advance for any help!!