For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC B2345 00: Seat Heater Disable Circuit
DTC B2345 4B: Seat Heater Disable Circuit Calibration Not Learned
DTC B2345 13: Seat Heater Disable Circuit Voltage Low/High Temperature
DTC B2345 42: Seat Heater Disable Circuit Calibration Data Set Not Programmed

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Driver Heated Seat Element Supply Voltage | B2345 00, B2508 02 | B2425 0C, B2425 0D | B2345 00, B2508 01 | --
Driver Heated Seat Element Control | B2345 00, B2508 02 | B2425 0C, B2425 0D | B2345 00, B2508 01 | --
Driver Heated Seat Temperature Sensor Signal | B1925 02 | B1925 05, B2425 04, B2425 1F | B1925 05, B2425 04, B2425 1F | B2345 13, B2345 42, B2345 4B
Driver Heated Seat Temperature Sensor Low Reference | -- | B1925 05, B2425 04, B2425 1F | -- | B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Element Supply Voltage | B2345 00, B2508 02 | B2430 0C, B2430 0D | B2345 00, B2508 01 | --
Passenger Heated Seat Element Control | B2345 00, B2508 02 | B2430 0C, B2430 0D | B2345 00, B2508 01 | --
Passenger Heated Seat Temperature Sensor Signal | B2170 02 | B2170 05, B2430 04, B2430 1F | B2170 05, B2430 04, B2430 1F | B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Temperature Sensor Low Reference | -- | B2170 05, B2430 04, B2430 1F | -- | B2345 13, B2345 42, B2345 4B

### Circuit/System Description

The driver and passenger heated seat heating elements are controlled by a common high current relay internal to the heated seat module (HSM) and by individual low side element control circuits. The HSM connects the heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2 volts. Before the HSM will allow heated seat operation, it checks to see if the heating element supply voltage circuits and control circuits are shorted to ground or voltage. Once the module verifies that it is not closing into a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted a circuit.

### Conditions for Running the DTC

The HSM must be powered.

### Conditions for Setting the DTC

#### B2345 00

After the heated seat is activated, the HSM detects a short on either the heating element supply voltage circuit or control circuit.

#### B2345 13

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

#### B2345 42

This DTC will set if the module calibration is not programmed.

#### 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 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

#### Connector End View Reference

Heated/Cooled Seat Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Testing

#### B2345 00

1. Ignition OFF, disconnect the C1 harness connector at the HSM.
2. Test for infinite resistance between the control circuit terminal 3 and ground.

⇒ | If less than the specified range, test the control circuit for a short to ground.

3. Test for infinite resistance between the control circuit terminal 6 and ground.

⇒ | If less than the specified range, test the control circuit for a short to ground.

4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground.

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage.

5. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 6 and ground.

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage.

6. If all circuits test normal, replace the HSM.

#### B2345 13

1. Ignition OFF, disconnect the C2, C4 harness connector at the HSM.
2. Test for greater than 1.9K ohms between the signal and low reference circuits listed below:

• | Driver seat cushion terminal 9 C4 and terminal 6 C2

• | Passenger seat cushion terminal 20 C4 and terminal 8 C2

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

3. If all circuits test normal, replace the HSM.

#### B2345 42 or B2345 4B

If either DTC is set, replace the HSM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Driver or Passenger Seat Back Cushion Heater Replacement

• | Driver or Passenger Seat Cushion Heater Replacement

• | Control Module References for the HSM replacement, setup, and programming