2010 Cadillac Truck SRX FWD V6-3.0L Page 152

2010 Cadillac Truck SRX FWD V6-3.0L Page 152

- Auxiliary Heater System Malfunction

Circuit/System Description

The HVAC control module sends a pulse width modulation (PWM) signal to the electrical auxiliary heater, if the interior temperature is too low

and additional heat is requested. The request signal from the HVAC control module, battery positive, ignition and ground circuits enable the

electrical auxiliary heater to operate. Through the signal circuit the electrical auxiliary heater sends via a PWM signal the current status to the

HVAC control module.

Conditions for Running the DTC

* Ignition ON.

* The HVAC control module is ON.

* The electrical auxiliary heater is ON.

Conditions for Setting the DTC

B048D 01

The voltage at the HVAC control module output to the electrical auxiliary heater is always high.

B048D 06

The voltage at the HVAC control module output to the electrical auxiliary heater is always low or floating.

B048E 00

The feedback signal of the electrical auxiliary heater does not correspond with the requested PWM signal.

Action Taken When the DTC Sets

The electrical auxiliary heater is inoperative.

Conditions for Clearing the DTC

The feedback signal of the electrical auxiliary heater corresponds with the requested PWM signal.

Reference Information

Schematic Reference

HVAC Schematics (See: Heating and Air Conditioning/Diagrams/Electrical Diagrams)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)

Description and Operation

Automatic HVAC Description and Operation (See: Heating and Air Conditioning/Description and Operation)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Verify that DTC B048D 01 or B048D 06 is not set.

瀚慖f DTC is present, refer to Electrical Auxiliary Heater Control Circuit Malfunction.

2. Verify that DTC B048E 00 is not set.