When I turn on the 4 x4 switch in dash nothing happens
Visual Inspection Chart
Mechanical
Electrical
I'm assuming you 4x4 is electronic (switch On Dash ) .
If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
If the cause is not visually evident, connect the diagnostic tool to the data link connector and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle
check that the program card is correctly installed (if using NGS+).
check the connections to the vehicle.
check the ignition switch position.
If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
Carry out the data link diagnostics test. If the diagnostic tool responds with:
SCP+, SCP-, UBP, CAN or ISO circuits fault; all electronic control units no response/not equipped, refer to Section 418-00 .
No response/not equipped for powertrain control module (PCM). Refer to Section 418-00 to diagnose module communication problems.
No response/not equipped for 4WD control module, Go To Pinpoint Test A .
System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the self-test diagnostics for the 4WD control module.
If the DTCs retrieved are related to the concern, go to the 4WD control module (PCM) DTC Index to continue diagnostics.
If no DTCs related to the concern are retrieved, GO to Symptom Chart .
Have it checked for DTC'S - diagnostic trouble codes. Does the 4X4 switch light up ?
Principles of Operation
The electronic shift on the fly (ESOF) system is an electronic shift system that allows the operator to choose between 2 different 4-wheel drive modes as well as 2-wheel drive. The operator can switch between 2WD and 4H mode at speeds up to 88 km/h (55 mph). To engage or disengage 4L range, the vehicle speed must be less than 5 km/h (3 mph), the brake pedal pressed and the transmission must be in NEUTRAL (or the clutch pedal pressed in manual transmission vehicles).
When the mode select switch (MSS) on the instrument panel is turned, the 4WD control module (PCM) activates the electromagnetic clutch and powers the transfer case shift motor. When the shift motor reaches the desired position, as determined by the contact plate position inputs to the 4WD control module (PCM), power to the shift motor will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket. Finally, the front axle integrated wheel ends (IWEs) are engaged and the electromagnetic clutch is deactivated.
Feature Inputs:
Mode select switch (MSS)
Wheel speeds (via CAN communication)
Contact plate position inputs A, B, C, D (grounded when closed, open circuit when open)
Transmission neutral
Brake ON/OFF (BOO)
Feature Outputs:
Transfer case synchronization clutch
Transfer case shift motor relays
Integrated wheel-end (IWE) vacuum solenoid
Instrument cluster indicators (via CAN communication)
4WD mode (via CAN communication to PCM)
×
333 views
Usually answered in minutes!
×