B1023

DTC B1023

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.

DTC Descriptor
DTC B1023 00
- CAN Bus Error

Diagnostic Fault Information





Circuit/System Description

The telematic vehicle localization and immobilization control module communicates with the scan tool via the keyword 2000 serial data circuit. The keyword 2000 system is for diagnostics of the telematic vehicle localization and immobilization control module only. There is no communication between any other control modules on the keyword 2000 serial data system.

Conditions for Running the DTC

The system voltage is between 9-16 V.

Conditions for Setting the DTC

A supervised periodic message that includes the transmitter module availability has not been received.

Action Taken When the DTC Sets

Specific subsystems will not function.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

Reference Information
Schematic Reference

* Control Module References (Programming and Relearning)
* Data Communication Schematics ([1][2]Electrical Diagrams)

Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Data Link Communications Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

Circuit/System Testing

Note: Use the schematic to identify the control module B+, ignition, ground, and serial data circuit terminals.

1. Ignition OFF, disconnect the harness connector at the telematic vehicle localization and immobilization control module.
2. Test for less than 10 ohm between each ground circuit terminal and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. If equipped, ignition ON, verify that a test lamp illuminates between each B+ circuit terminal and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the telematic vehicle localization and immobilization control module for a short to ground. If the circuits test normal, replace the telematic vehicle localization and immobilization control module.

4. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.

• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the telematic vehicle localization and immobilization control module for a short to ground. If the circuits test normal, replace the telematic vehicle localization and immobilization control module.

5. Test for infinite resistance between the data link connector (DLC) keyword 2000 serial data circuit terminal 7 and ground.

• If less than the specified range, test the serial data circuit for a short to ground.

6. Test for less than 1 V between the DLC keyword 2000 serial data circuit terminal 7 and ground.

• If greater than the specified range, test the serial data circuit for a short to voltage.

7. Test for less than 5 ohm in the keyword 2000 serial data circuit between the telematic vehicle localization and immobilization control module keyword 2000 serial data circuit terminal and the DLC terminal 7.

• If greater than the specified range, test the serial data circuit for an open/high resistance.

8. If all circuits test normal, replace the telematic vehicle localization and immobilization control module.

Repair Instructions

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

Control Module References (Programming and Relearning)for control module replacement, programming and setup