Scan Tool Does Not Communicate with Keyword Data Line

Scan Tool Does Not Communicate with Keyword Data Line

Diagnostic Instructions

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



Diagnostic Fault Information






Circuit/System Description

The climate control seat module (CCSM) communicates with a scan tool via the keyword 2000 serial data circuit. The keyword 2000 system is for diagnostics of the CCSM only. There is no communication between any other modules on the keyword 2000 serial data system.


Diagnostic Aids

Some modules may not have internal protection for specific voltage outputs and may open a battery positive voltage or ignition voltage source fuse. If a voltage input fuse is open and no short is found in that circuit, ensure that no module output voltage circuit is shorted to ground before replacing the module.


Reference Information
Schematic Reference

* Heated/Cooled Seat Schematics (Electrical Diagrams)
* Data Communication Schematics (Electrical Diagrams)

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

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

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) for scan tool information


Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors X1, X2, and X3 of the CCSM.
2. Test for less than 1 ohm of resistance between the module ground circuit terminal M X1 and ground.

• If greater than 1 ohm, repair the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between battery positive voltage circuit terminal E X1 and ground.

• If the test lamp does not illuminate, repair the battery positive voltage circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the CCSM.

4. Ignition ON, verify that a test lamp illuminates between ignition voltage circuit terminal 1 X2 and ground.

• If the test lamp does not illuminate, repair the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the CCSM.

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 value, test the serial data circuit for a short to ground.

6. Test for less than 1 volt 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 1 ohm of resistance in the keyword 2000 serial data circuit between the CCSM terminal 9 X3 and the DLC terminal 7.

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

8. If all circuits test normal, replace CCSM.



Repair Instructions

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


Programming and Relearning (Programming and Relearning) for CCSM replacement, setup, and programming