2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 2031

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 2031

Testing the Serial Data Circuits for a Open/High Resistance

1. Ignition OFF, disconnect the harness connectors with the mid speed or chassis high speed serial data circuits at an easily accessible control

module, that is not communicating.

2. Ignition OFF for 60 seconds, test for greater than 130 ohm between each pair of serial data circuits. Verify that one pair of serial data circuits

are greater than 130 ohm.

瀚慖f less than the specified range for each pair of serial data circuits, replace the control module that was disconnected.

3. Connect the harness connectors at the control module that was disconnected.

4. Disconnect the harness connectors with the mid speed or chassis high speed serial data circuits at another control module, in the direction of

the open circuit.

5. Ignition OFF for 60 seconds, test for greater than 130 ohm between each pair of serial data circuits. Verify that one pair of serial data circuits

are greater than 130 ohm.

6. Repeat step 3 until one of the following conditions are isolated:

* An open/high resistance on the serial data circuit between 2 control modules

* An open/high resistance on the serial data circuit between a control module and a terminating resistor

* An open/high resistance terminating resistor

Testing the Ignition Circuit

1. Ignition OFF, disconnect the harness connectors with the ignition circuits at an easily accessible control module that is not communicating.

2. Ignition OFF, verify that a test lamp does not illuminate between each ignition circuit terminal and ground, at the control module connector

that was just disconnected.

瀚慖f the test lamp does illuminate, test the ignition circuit for a short to voltage. If the circuits test normal, replace the control module that

was just disconnected.

3. Ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

瀚慖f the circuits test normal, replace the control module that was just disconnected.

4. Connect the harness connectors at the control module that was just disconnected.

5. Repeat step 1 at another control module until a short to voltage, a short to ground, or an open/high resistance is found on the ignition circuits.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.

* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Wiring Repairs/GMLAN Wiring Repairs)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, programming and

setup

U0100

DTC U0100-U02FF

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

Refer to Control Module U Code List (See: Diagnostic Trouble Code Descriptions/Control Module U Code List).

Diagnostic Fault Information