Operation CHARM: Car repair manuals for everyone.

B2345



DTC B2345

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy 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.


DTC Descriptors
DTC B2345 13
- Front Seat Heater Temperature Above Threshold

DTC B2345 42
- Front Seat Heater Current Sensing Calibration Not Present

DTC B2345 4B
- Seat Heater Current Sensing Calibration data Out of Range



Diagnostic Fault Information





Circuit/System Description

The driver and passenger heated seat heating elements are controlled by a common high current relay internal to the memory seat module (MSM) and the low side by individual element control circuits. The MSM connects the heated seat heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2.0 volts. Before the MSM will allow heated seat operation, it checks to see if this reference voltage is shorted to ground or battery voltage. Once the module verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

Conditions for Running the DTC

The MSM must be powered.

Conditions for Setting the DTC

B2345 13

Any temperature sensor input that remains below 1.5 volts for more than 1 second.

B2345 42

This DTC will set if the module calibration data set is not present.

B2345 4B

This DTC will set if the module calibration is out of range.

Action Taken When the DTC Sets

The heated seat function for both seats will be disabled.

Conditions for Clearing the DTC

* The current DTC will clear and set the code to history 3 seconds after the reference voltage returns to the normal operating range and the ignition is cycled OFF then back to ACC or RUN.
* The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.


Reference Information
Schematic Reference

Heated/Cooled Seat Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Heated Seats Description and Operation (Heated Seats 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

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

Circuit/System Testing

B2345 13
1. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
2. Test for greater than 3.0K ohms between the signal circuit and the low reference circuits listed below:

* Driver seat cushion terminal 1 X5 and terminal 3 X2
* Passenger seat cushion terminal 2 X5 and terminal 6 X2

If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat cushion temperature sensor.

3. Test for greater than 2.4K ohms between the signal circuit and the low reference circuits listed below:

* Driver seat back terminal 4 X5 and terminal 2 X2
* Passenger seat back terminal 3 X5 and terminal 5 X2

If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat back temperature sensor.

4. If all circuits test normal, replace the MSM.

B2345 42 or B2345 4B

If either DTC is set, replace the MSM.

Repair Instructions

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

* Driver or Passenger Seat Back Cushion Heater Replacement (Driver or Passenger Seat Back Cushion Heater Replacement)
* Driver or Passenger Seat Cushion Heater Replacement (Driver or Passenger Seat Cushion Heater Replacement)
* Control Module References (Programming and Relearning) for MSM replacement, setup and programming