2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 617

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 617

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

* Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2) ()Driver or Passenger Seat Back Cushion Heater

Replacement (Tahoe with HP2) ()Driver or Passenger Seat Back Cushion Heater Replacement (without HP2) ()

* Driver or Passenger Seat Cushion Heater Replacement (without HP2) ()Driver or Passenger Seat Cushion Heater Replacement (with HP2)

()

* Control Module References (See: Testing and Inspection/Programming and Relearning) for the HSM replacement, setup, and programming

Rear Seat

DTC B2508 or B2509 (Rear Seat)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC B2508 01

- Seat Heater Relay Circuit Short to Battery

DTC B2508 02

- Seat Heater Relay Circuit Short to Ground

Diagnostic Fault Information

Circuit/System Description

The rear seat heating elements are controlled by a common high current relay internal to the rear heated seat module (RHSM) and on the low side

by individual element control circuits. The RHSM connects the seat heater element supply voltage circuits to a common reference point. This

reference point is biased to approximately 2.5 V. Before the RHSM will allow heated seat operation, it checks to see if the heating element supply

voltage circuits and control circuits are shorted to ground or battery voltage. Once the RHSM 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 RHSM must be powered.

Conditions for Setting the DTC

B2508 02

Before the heated seats are activated, the RHSM detects a short to ground on the seat heating element supply voltage circuit or control circuit.