Chevrolet Silverado / GMC Sierra. Service manual — part 2753

B2345 13

Any of the temperature sensor inputs remains below 1.5 volts for a seat back or 0.95 volts for a
seat cushion more than 1 second.

B2345 42

The current sensing calibration data is out of range.

B2345 4B

The current sensing calibration data is not programmed.

Action Taken When the DTC Sets

The heated seat functions for both 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

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Seat Heating and Cooling - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

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 driver seat heating element supply voltage circuit

terminal 14 X1 and ground.

If less than the specified range, test the supply voltage circuit and the seat cushion and
seat back heating element control circuits for a short to ground.

3. Ignition ON, verify that a test lamp does not illuminate between the supply voltage circuit

terminal 14 X1 and ground.

If the test lamp illuminates, test the supply voltage circuit and the seat cushion and seat
back heating element control circuits for a short to voltage.

4. Test for infinite resistance between the passenger seat heating element supply voltage circuit

terminal 6 X1 and ground.

If less than the specified range, test the supply voltage circuit and the seat cushion and
seat back heating element control circuits for a short to ground.

5. Ignition ON, verify that a test lamp does not illuminate between the supply voltage circuit

terminal 6 X1 and ground.

If the test lamp illuminates, test the supply voltage circuit and the seat cushion and seat
back heating element control circuits for a short to voltage.

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 850 ohms between the following seat cushion temperature sensor signal

circuits and the low reference circuits:

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 affected seat cushion heater element.

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Seat Heating and Cooling - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

3. Test for greater than 850 ohms between the following seat back temperature sensor signal

circuits and the low reference circuits:

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 affected seat back heater element.

4. If the circuits test normal replace the MSM.

B2345 42 or B2345 4B

If this DTC is retrieved as a current DTC, replace the MSM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Driver Seat and Passenger Seat Back Cushion Heater Replacement

Driver Seat and Passenger Seat Cushion Heater Replacement

Control Module References for the MSM replacement, setup, and programming

DTC B2425 OR B2430

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 B2425 04

Left Seat Cushion Heater Circuit Open

DTC B2425 0A

Left Seat Cushion Heater Circuit Rate of Change Below Threshold

DTC B2425 0B

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Seat Heating and Cooling - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Left Seat Cushion Heater Circuit Current Above Threshold

DTC B2425 0C

Left Seat Cushion Heater Circuit Current Below Threshold

DTC B2425 0D

Left Seat Heater Cushion Circuit Resistance Above Threshold

DTC B2425 0E

Left Seat Heater Cushion Circuit Resistance Below Threshold

DTC B2425 1F

Left Seat Cushion Heater Circuit Intermittent

DTC B2430 04

Right Seat Cushion Heater Circuit Open

DTC B2430 0A

Right Seat Cushion Heater Circuit Rate of Change Below Threshold

DTC B2430 0B

Right Seat Cushion Heater Circuit Current Above Threshold

DTC B2430 0C

Right Seat Cushion Heater Circuit Current Below Threshold

DTC B2430 0D

Right Seat Heater Cushion Circuit Resistance Above Threshold

DTC B2430 0E

Right Seat Heater Cushion Circuit Resistance Below Threshold

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Seat Heating and Cooling - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado