Chevrolet Silverado / GMC Sierra. Service manual — part 2693

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.

2. Test for infinite resistance between each seat direction signal terminal and the switch B+

terminal with the switch in the open position.

If not Inactive, test the signal circuit that displays Active for a short to voltage. If the
circuit tests normal, replace the MSM.

3. If all circuits test normal, test or replace the seat adjuster switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.

2. Test for infinite resistance between each seat direction signal terminal and the switch B+

terminal with the switch in the open position.

If less than infinite resistance, replace the switch.

3. Test for less than 1 ohm of resistance between each seat direction signal terminal and the B+

terminal with the switch in the closed position.

If greater than 1 ohm, replace the switch.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Power Seat Switch Replacement

Control Module References for memory seat module replacement, setup, and
programming

DTC B1825, B1850, B1860, B2355, B2365, OR B2375

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 B1825 01

Driver Seat Recline Position Sensor Circuit Short to Battery

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Power Seats - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

DTC B1825 06

Driver Seat Recline Position Sensor Circuit Short to Ground or Open

DTC B1825 5A

Driver Seat Recline Position Sensor Circuit Plausibility Failure

DTC B1850 01

Driver Seat Lumbar Horizontal Position Sensor Circuit Short to Battery

DTC B1850 06

Driver Seat Lumbar Horizontal Position Sensor Circuit Short to Ground or Open

DTC B1850 5A

Driver Seat Lumbar Horizontal Position Sensor Circuit Plausibility Failure

DTC B1860 01

Driver Seat Lumbar Vertical Position Sensor Circuit Short to Battery

DTC B1860 06

Driver Seat Lumbar Vertical Position Sensor Circuit Short to Ground or Open

DTC B1860 5A

Driver Seat Lumbar Vertical Position Sensor Circuit Plausibility Failure

DTC B2355 01

Driver Seat Front Vertical Position Sensor Circuit Short to Battery

DTC B2355 06

Driver Seat Front Vertical Position Sensor Circuit Short to Ground or Open

DTC B2355 5A

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Power Seats - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Driver Seat Front Vertical Position Sensor Circuit Plausibility Failure

DTC B2365 01

Driver Seat Rear Vertical Position Sensor Circuit Short to Battery

DTC B2365 06

Driver Seat Rear Vertical Position Sensor Circuit Short to Ground or Open

DTC B2365 5A

Driver Seat Rear Vertical Position Sensor Circuit Plausibility Failure

DTC B2375 01

Driver Seat Assembly Horizontal Position Sensor Circuit Short to Battery

DTC B2375 06

Driver Seat Assembly Horizontal Position Sensor Circuit Short to Ground or Open

DTC B2375 5A

Driver Seat Assembly Horizontal Position Sensor Circuit Plausibility Failure

Circuit Description

The position sensor that sets this diagnostic trouble code (DTC) is either attached to the seat
directional motor drive cable or directly to the motor it monitors. It receives a 5-volt reference
and ground from the memory seat module (MSM). The sensor sends a voltage signal that varies
with the movement of the seat through the signal circuit to the MSM. Then based on this voltage
signal, the MSM determines the position of the seat.

Conditions for Running the DTC

The memory seat module must be powered.

Conditions for Setting the DTC

B1825, B1850, B1860, B2355, B2365, B2375 01

If the MSM sees the analog input from this sensor is greater than 4.65 volts, the sensor will be

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Power Seats - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

considered out of range and the MSM will set this DTC.

B1825, B1850, B1860, B2355, B2365, B2375 06

If the MSM sees the analog input from this sensor is less than 0.27 volt, the sensor will be
considered out of range and the MSM will set this DTC.

B1825, B1850, B1860, B2355, B2365, B2375 5A

This DTC will set, if the MSM is controlling a motor in one direction and it's position sensor is
tracking the motor in the opposite direction. The sensor is either mounted or wired incorrectly, or
the polarity of the motor control circuits are reversed.

Action Taken When the DTC Sets

The MSM disables the memory recall and easy exit/entry action commands of the motor
monitored by the sensor. The motor will respond to manual positioning commands.

Conditions for Clearing the DTC

The current DTC will clear and set to history, when the MSM sees the analog input from the
sensor as between 0.27-4.65 volts and the ignition is cycled OFF then back to ACC or
RUN.

A history DTC will clear after 50 ignition cycles or with a scan tool using the clear DTCs
function.

Diagnostic Aids

All position sensors use common ground and 5-volt reference circuits.

If the 5-volt reference circuit is shorted to voltage, multiple codes will set.

If the 5-volt reference circuit is shorted to ground, multiple codes will set.

If the sensor ground circuit is open, multiple codes will set.

Reference Information

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Component Connector End Views

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Power Seats - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado