For 1990-2009 cars

## DTC B2345 With Memory A45

### 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 Descriptor

DTC B2345 00: Front Seat Heater Disable Circuit
DTC B2345 13: Front Seat Heater Temperature Above Threshold
DTC B2345 42: Front Seat Heater Current Sensing Calibration Data Not Present
DTC B2345 4B: Front Seat Heater Current Sensing Calibration Data Out of Range

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
B+ MSM Terminal 5 X3 | 1, 2, B1935 0C, B1935 0D, B2180 0C, B2180 0D, B2425 0C, B2425 0D, B2430 0C, B2430 0D | 1, 2, B1935 0C, B1935 0D, B2180 0C, B2180 0D, B2425 0C, B2425 0D, B2430 0C, B2430 0D | -- | --
Driver Heated Seat Back Element Supply Voltage | B2508 02 | B1935 0C, B1935 0D | B2345 00, B2508 01 | B1935 0B, B1935 0E
Driver Heated Seat Back Element Control | B2345 00, B2508 02 | B1935 0C, B1935 0D | B2345 00, B2508 01 | B1935 0B, B1935 0E
Driver Heated Seat Back Temperature Sensor Signal | B2435 02 | B1935 04, B1935 1F, B2435 0D | B1935 04, B1935 1F, B2435 0D | B1935 0A, B2345 13, B2345 42, B2345 4B
Driver Heated Seat Back Temperature Sensor Low Reference | -- | B1935 04, B1935 1F, B2435 0D | -- | B2345 13, B2345 42, B2345 4B
Driver Heated Seat Cushion Element Supply Voltage | B2508 02 | B2425 0C, B2425 0D | B2345 00, B2508 01 | B2425 0B, B2425 0E
Driver Heated Seat Cushion Element Control | B2345 00, B2508 02 | B2425 0C, B2425 0D | B2345 00, B2508 01 | B2425 0B, B2425 0E
Driver Heated Seat Cushion Temperature Sensor Signal | B1925 02, B2425 1F | B1925 05, B2425 04, B2425 1F | B1925 05, B2425 04, B2425 1F | B2345 13, B2345 42, B2345 4B, B2425 0A
Driver Heated Seat Cushion Temperature Sensor Low Reference | -- | B1925 05, B2425 04, B2425 1F | -- | B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Back Element Supply Voltage | B2508 02 | B2180 0C, B2180 0D | B2345 00, B2508 01 | B2180 0B, B2180 0E
Passenger Heated Seat Back Element Control | B2345 00, B2508 02 | B2180 0C, B2180 0D | B2345 00, B2508 01 | B2180 0B, B2180 0E
Passenger Heated Seat Back Temperature Sensor Signal | B2440 02 | B2180 04, B2180 1F, B2440 05 | B2180 04, B2180 1F, B2440 05 | B2180 0A, B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Back Temperature Sensor Low Reference | -- | B2180 04, B2180 1F, B2440 05 | -- | B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Cushion Element Supply Voltage | B2508 02 | B2430 0C, B2430 0D | B2345 00, B2508 01 | B2430 0B, B2430 0E
Passenger Heated Seat Cushion Element Control | B2345 00, B2508 02 | B2430 0C, B2430 0D | B2345 00, B2508 01 | B2430 0B, B2430 0E
Passenger Heated Seat Cushion Temperature Sensor Signal | B2170 02, B2430 1F | B2430 04, B2430 1F, B2170 05 | B2430 04, B2430 1F, B2170 05 | B2345 13, B2345 42, B2345 4B, B2430 0A
Passenger Heated Seat Cushion Temperature Sensor Low Reference | -- | B2430 04, B2430 1F, B2170 05 | -- | B2345 13, B2345 42, B2345 4B
1. Power seat inoperative 2. Heated seat inoperative

### 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 00

After the heated seat is activated, the MSM detects a shorted circuit on the seat heating element supply voltage circuit or control circuit.

#### 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 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 functions for both front seats will be disabled.

### Conditions for Clearing the DTC

• | The current DTC clears when the malfunction is no longer present and the power mode changes to 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

Component Connector End Views

#### Description and Operation

Heated Seats Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

#### B2345 00

1. Ignition OFF, disconnect the X1, X4 harness connectors at the MSM.
2. Test for infinite resistance between the control circuit terminal 6 X1 and ground.

⇒ | If not the specified value, test the control circuits listed below for a short to ground:

• | Driver seat cushion and seat back terminal 6 X1

• | Driver seat cushion element terminal 11 X1

• | Driver seat back element terminal 1 X1

3. Test for infinite resistance between the control circuit terminal 14 X1 and ground.

⇒ | If not the specified value, test the control circuits listed below for a short to ground:

• | Passenger seat cushion and seat back terminal 14 X1

• | Passenger seat cushion element terminal 14 X4

• | Passenger seat back element terminal 4 X1

4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 6 X1 and ground.

⇒ | If the test lamp illuminates, test the control circuits listed below for a short to voltage:

• | Driver seat cushion and seat back terminal 6 X1

• | Driver seat cushion element terminal 11 X1

• | Driver seat back element terminal 1 X1

5. Verify that a test lamp does not illuminate between the control circuit terminal 14 X1 and ground.

⇒ | If the test lamp illuminates, test the control circuits listed below for a short to voltage:

• | Passenger seat cushion and seat back terminal 14 X1

• | Passenger seat cushion element terminal 14 X4

• | Passenger seat back element terminal 4 X1

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

#### B2345 13

1. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
2. Test for greater than 3.3K ohms between the signal 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 3.3K ohms between the signal 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 after completing the diagnostic procedure.

• | Driver or Passenger Seat Back Cushion Heater Replacement

• | Driver or Passenger Seat Cushion Heater Replacement

• | Control Module References for MSM replacement, setup, and programming

## DTC B2345 Without Memory A45

### 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: Front Seat Heater Disable Circuit
DTC B2345 13: Front Seat Heater Temperature Above Threshold
DTC B2345 42: Front Seat Heater Current Sensing Calibration Data Not Present
DTC B2345 4B: Front Seat Heater Current Sensing Calibration Data Out of Range

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Driver Heated Seat Back Element Supply Voltage | B2508 02 | B1935 0C, B1935 0D | B2345 00, B2508 01 | B1935 0B, B1935 0E
Driver Heated Seat Back Element Supply Control | B2345 00, B2508 02 | B1935 0C, B1935 0D | B2345 00, B2508 01 | B1935 0B, B1935 0E
Driver Heated Seat Back Temperature Sensor Signal | B2435 02 | B1935 04, B1935 1F, B2435 0D | B1935 04, B1935 1F, B2435 0D | B1935 0A, B2345 13, B2345 42, B2345 4B
Driver Heated Seat Back Temperature Sensor Low Reference | -- | B1935 04, B1935 1F, B2435 0D | -- | B2345 13, B2345 42, B2345 4B
Driver Heated Seat Cushion Element Supply Voltage | B2508 02 | B2425 0C, B2425 0D | B2345 00, B2508 01 | B2425 0B, B2425 0E
Driver Heated Seat Cushion Element Control | B2345 00, B2508 02 | B2425 0C, B2425 0D | B2345 00, B2508 01 | B2425 0B, B2425 0E
Driver Heated Seat Cushion Temperature Sensor Signal | B1925 02, B2425 1F | B1925 05, B2425 04, B2425 1F | B1925 05, B2425 04, B2425 1F | B2345 13, B2345 42, B2345 4B, B2425 0A
Driver Heated Seat Cushion Temperature Sensor Low Reference | -- | B1925 05, B2425 04, B2425 1F | -- | B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Back Element Supply Voltage | B2508 02 | B2180 0C, B2180 0D | B2345 00, B2508 01 | B2180 0B, B2180 0E
Passenger Heated Seat Back Element Control | B2345 00, B2508 02 | B2180 0C, B2180 0D | B2345 00, B2508 01 | B2180 0B, B2180 0E
Passenger Heated Seat Back Temperature Sensor Signal | B2440 02 | B2180 04, B2180 1F, B2440 05 | B2180 04, B2180 1F, B2440 05 | B2180 0A, B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Back Temperature Sensor Low Reference | -- | B2180 04, B2180 1F, B2440 05 | -- | B2345 13, B2345 42, B2345 4B
Passenger Heated Seat Cushion Element Supply Voltage | B2508 02 | B2430 0C, B2430 0D | B2345 00, B2508 01 | B2430 0B, B2430 0E
Passenger Heated Seat Cushion Element Control | B2345 00, B2508 02 | B2430 0C, B2430 0D | B2345 00, B2508 01 | B2430 0B, B2430 0E
Passenger Heated Seat Cushion Temperature Sensor Signal | B2170 02, B2430 1F | B2430 04, B2430 1F, B2170 05 | B2430 04, B2430 1F, B2170 05 | B2345 13, B2345 42, B2345 4B, B2430 0A
Passenger Heated Seat Cushion Temperature Sensor Low Reference | -- | B2430 04, B2430 1F, B2170 05 | -- | 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 heated seat module 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 passenger 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

Component Connector End Views

#### Description and Operation

Heated Seats Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

#### B2345 00

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for infinite resistance between the control circuit terminal 3 and ground.

⇒ | If not the specified value, test the control circuits listed below for a short to ground.

• | Driver seat cushion and seat back terminal 3

• | Driver seat cushion element terminal 5

• | Driver seat back element terminal 1

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

⇒ | If not the specified value, test the control circuits listed below for a short to ground.

• | Passenger seat cushion and seat back terminal 6

• | Passenger seat cushion element terminal 2

• | Passenger seat back element terminal 4

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 circuits listed below for a short to voltage.

• | Driver seat cushion and seat back terminal 3

• | Driver seat cushion element terminal 5

• | Driver seat back element terminal 1

5. Verify that a test lamp does not illuminate between the control circuit terminal 6 and ground.

⇒ | If the test lamp illuminates, test the control circuits listed below for a short to voltage.

• | Passenger seat cushion and seat back terminal 6

• | Passenger seat cushion element terminal 2

• | Passenger seat back element terminal 4

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

#### B2345 13

1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for greater than 3.3K ohms between the signal and the low reference circuits listed below:

• | Driver seat cushion terminal 9 X4 and terminal 6 X2

• | Passenger seat cushion terminal 20 X4 and terminal 8 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/heater element.

3. Test for greater than 3.3K ohms between the signal and the low reference circuits listed below:

• | Driver seat back terminal 19 X4 and terminal 5 X2

• | Passenger seat back terminal 10 X4 and terminal 7 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/heater element.

4. 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 HSM replacement, setup, and programming