Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category |
DTC Descriptor
DTC B0770 01: AWD Indicator Circuit Short to BatteryDTC B0770 06: AWD Indicator Circuit Short to Ground or Open
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
AWD Indicator Circuit | DTC B0770 06 | DTC B0770 06 | DTC B0770 01 | -- |
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 10-18 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 is not commanded on for this DTC.
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 40 consecutive warm up cycles without a fault present. |
| • | History DTCs can be cleared using a scan tool. |
Reference Information
Schematic Reference
Transfer Case Control Schematics
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information.
Diagnostic Aids
A short to ground on the AWD indicator control circuit will cause the AWD indicator to remain on at all times. An open or high resistance will cause the AWD indicator to be inoperative during the 2 second bulb check.
Circuit/System Testing
Check the interior dimming circuit pin 2 at the transfer case shift control switch for voltage for the 2 seconds after turning the ignition on during the bulb check.
| ⇒ | If less than battery voltage check the interior dimming circuit for an open or high resistance. If the voltage is low or non existence and the circuit tests good replace the BCM. If the interior dimming circuit and BCM test good go to the next step. |
| ⇒ | If the AWD indicator is on at all times check the AWD indicator control circuit for a short to ground. If the AWD indicator is inoperative during bulb check, check the AWD indicator control circuit for an open or high resistance or short to voltage. If the circuit checks good continue to the next step. |
| ⇒ | With the ignition on shift the transmission to neutral and using transfer case output controls attempt to command the AWD indicator off and on. If the AWD indicator is still inoperative short to AWD indicator to ground, if the AWD indicator lights replace the module. If the AWD indicator is still inoperative replace the switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for TCSCM replacement, setup, and programming |
