B0481

DTC B0481, B0482, or B0483

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0481 00

-
Overheat Detected, Software Level

DTC B0482 00

-
Overheat Detected, Hardware Level

DTC B0483 00

-
Overheat Possible

Circuit/System Description

The fuel operated heater uses a coolant heater overheat sensor to protect the unit for over temperature conditions. The fuel operated heater also uses overheat detection software.

Conditions for Running the DTC

Engine is running.

Conditions for Setting the DTC

The fuel operated heater has recognized an over temperature condition.

Action Taken When the DTC Sets

The fuel operated coolant heater is disabled.

Conditions for Clearing the DTC

* A current DTC will clear when the conditions for setting the DTC are no longer present.

* A history DTC will clear after 40 malfunction-free ignition cycles.

Reference Information

Schematic Reference

HVAC Schematics Electrical DiagramsHVAC Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

Air Temperature Description and Operation Air Temperature

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, verify DTC B0460 or B0462 is not set.

• If either DTC is set, refer to DTC B0460 or B0462 B0460.

2. If all circuits test normal, replace the coolant heater.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

Heater Coolant Heater Replacement Heater Coolant Heater Replacement