2010 Cadillac Truck SRX FWD V6-3.0L Page 2177

2010 Cadillac Truck SRX FWD V6-3.0L Page 2177

Note: Use the schematic to determine which control modules are on the BCM communications enable circuit 23, X4.

1. Ignition OFF, disconnect the harness connector at the most easily accessible control module on the BCM communications enable circuit.

2. Ignition ON, retest for current DTCs. DTC U2099 should remain current.

瀚慖f the DTC becomes history, replace the control module.

3. With the prior control modules disconnected, repeat steps 1 and 2 for each control module on the circuit except the BCM.

4. Ignition OFF, disconnect the X 4 harness connector at the K9 BCM.

5. Test for infinite resistance between the serial data communication enable circuit terminal 23 and ground.

瀚慖f less than infinite resistance, repair the enable circuit for a short to ground.

6. If all circuits tests normal, replace the K9 BCM.

Repair Instructions

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

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

U2100

DTC U0073 or U2100

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 Descriptors

DTC U0073 00

- Control Module Communication Bus Off

DTC U0073 71

- ECU HS Bus Off

DTC U0073 72

- ECU LS Bus Off

DTC U2100 00

- Controller Area Network (CAN) Bus Communication

DTC U2100 47

- Controller Area Network (CAN) Bus Communication

Circuit/System Description

The serial data circuits are serial data buses are used to communicate information between the control modules. The serial data circuits also connect

directly to the data link connector (DLC).

Conditions for Running the DTCs

* Supply voltage at the control modules is in the normal operating range.

* The vehicle power mode requires serial data communications.

Conditions for Setting the DTC

The control module setting the DTC has attempted to establish communications on the serial data circuits more than 3 times in 5 seconds.

Action Taken When the DTCs Sets

* The control module suspends all message transmission.