B0483

DTC B0481, B0482, or B0483

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Air Temperature Description and Operation (HVAC Control Components)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) 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)