2010 Cadillac CTS Sedan AWD V6-3.6L Page 494
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
Doors unlocked, observe the function of the liftgate while pressing the liftgate handle switch, the liftgate latch should release the liftgate allowing
the liftgate to be pulled open.
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the K39 liftgate module.
2. Test for less than 5 ohm between the control circuit terminal 1 and the control circuit terminal 2.
瀚慖f greater than the specified range, test either control circuit for a short to voltage or an open/high resistance. If circuits test normal, test or
replace the M31 liftgate latch assembly.
3. Verify that a test lamp does not illuminate between the control circuit terminal listed below and B+:
* Control circuit terminal 1
* Control circuit terminal 2
瀚慖f the test lamp illuminates, test the control circuit for a short to ground. If circuit tests normal, test or replace the M31 liftgate latch
assembly.
4. Install a 30A fused jumper wire between one of the control terminals and 12 V. Momentarily install a jumper wire between the other control
terminal and ground. Reverse the jumper wires at least two times, the M31 liftgate latch assembly should perform the CINCH and RELEASE
functions.
瀚慖f it does not perform as specified, replace the M31 liftgate latch assembly.
5. If all circuits test normal, replace the K39 liftgate module.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
* Liftgate Latch Replacement (See: Body and Frame/Doors, Hood and Trunk/Trunk / Liftgate/Trunk / Liftgate Latch/Service and
Repair/Liftgate Latch Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for the liftgate module replacement, setup and
programming
B2503
DTC B2503
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC B2503 00
- Trunk/Liftglass/Hatch Key Switch Circuit
Diagnostic Fault Information
