C1296

EBCM/4WD Switch Schematic:

CIRCUIT DESCRIPTION
Current is supplied to the 4WD indicator lamp through the IG COIL METER fuse (hot with ignition switch in ON and START positions.) The 4WD switch is open when the transfer case is set in either 2H or N range.

In 2H Mode - CKT 2S02 is supplied with current flowing through the 4WD indicator lamp bulb filament. The Electronic Brake Control Module (EBCM) senses this current and determines the vehicle is in 2H mode.

In 4H/4L Mode - CKT 2S02 is grounded by the 4WD switch. This causes to turn on the 4WD indicator lamp and signals the EBCM that the vehicle is in 4WD.

CONDITIONS FOR SETTING THE DTC
This Diagnostic Trouble Code (DTC) will set when the following conditions are met:
^ This DTC can be set anytime after initialization is completed.
^ The EBCM detects an open in CKT 2S02.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, ABS is not disabled and the ABS indicator lamp will not be illuminated.

CONDITIONS FOR CLEARING THE DTC
^ Conditions for the malfunction are no longer present and the Tech 2 scan tool Clear DTC Information function is used.
^ One hundred drive cycles have passed with no malfunctions detected.

DIAGNOSTIC AIDS
The following list contains items that need to be inspected when diagnosing this system:
^ Open in CKT 2S02, lA01 and/or CKT 8B01.
^ Open 4WD indicator lamp bulb filament.
^ Open IG Coil METER fuse.

NOTE: The frequency of the malfunction can be checked by using the Enhanced Diagnostic function of the Tech 2 scan tool, as described in Enhanced Diagnostics.

An Intermittent Malfunction - may be caused by a poor connection, rubbed through wire insulation or a wire that is broken inside the insulation.

Any Circuitry That Is Suspected - of causing the intermittent complaint should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.

DTC C1296 4WD Switch Circuit Open (Part 1 Of 2):

DTC C1296 4WD Switch Circuit Open (Part 2 Of 2):

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
[1] Checks for an open IG COIL METER fuse.
[2] Checks the operation of the 4WD switch.
[3] Checks the operation of the 4WD indicator lamp circuit.
[4] Checks for an open 4WD indicator lamp bulb filament.
[5] Checks for an open in the power circuit (CKT 8B01) to the 4WD indicator lamp