B0770

DTC B0770

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 Descriptor
DTC B0770
- All Wheel Drive (AWD) Indicator Circuit Malfunction

Circuit/System Description

The All Wheel Drive (AWD) indicator circuit consists of an indicator lamp feed circuit and an AWD indicator lamp control circuit. When the AWD mode has been selected, current is supplied to the AWD indicator lamp by the indicator lamp feed circuit, traveling through the AWD indicator lamp LED, at which time the transfer case shift control module supplies the ground through the AWD indicator lamp control circuit.

Conditions for Running the DTC

* The ignition is ON.
* System voltage is 9-18 volts.

Conditions for Setting the DTC

* The system monitors the voltage on the AWD indicator control circuit.
* If the system detects a voltage of 2 volts or less for 1.5 seconds when the AWD indicator is not commanded, the DTC is logged.
* If the system detects a voltage of 4.5 volts or more when the AWD indicator is commanded, the DTC is logged.

Action Taken When the DTC Sets

The SERVICE 4WD indicator remains illuminated for the remainder of the current ignition cycle.

Conditions for Clearing the DTC

* The transfer case shift control module clears the DTC if the condition for setting the DTC is not currently present.
* A history DTC clears after 100 consecutive ignition cycles without a fault present.
* History DTCs can be cleared using a scan tool.

Reference Information
Schematic Reference

Transfer Case Control Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Transfer Case Description and Operation (NVG 226-NP8 - Transfer Case)
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.

Repair Instructions

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