Circuit Description
The accessory switch circuit consists of 4 modes. The transfer case shift control module supplies 5 volts to the switch through the switch signal circuit. The current travels through the resistor of the currently active mode. The current on the switch signal circuit is monitored by the transfer case shift control module. The voltage on the switch signal circuit will vary depending on which mode button is pressed by the driver.
The transfer case shift control module constantly monitors the switch signal circuit to determine the condition of the accessory switch circuit.
When each of the modes are selected they complete a circuit through their own specific resistor. The transfer case shift control module continuously monitors the switch signal circuit to determine whether the Neutral, 2HI, 4HI, or 4LO mode was selected by the driver.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Transfer Case Control Schematics Connector End View Reference: Transfer Case Control Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
Does the DMM indicate all resistance values within the specified ranges? | 4 HI: 656.2-669.4 ohms 2 HI: 1.50-1.53 K ohms Neutral: 1.010-1.031 K ohms 4 LO: 2.32-2.36 K ohms Normal: 9.00-9.18 K ohms | Go to Step 4 | Go to Step 3 | |
3 | Replace the accessory switch. Refer to Accessory Switch Replacement . Did you complete the repair? | -- | Go to Step 5 | -- |
4 | Replace the transfer case shift control module. Refer to Control Module References for replacement, setup, and programming. Did you complete the repair? | -- | Go to Step 5 | -- |
5 |
Is the symptom still present? | -- | Go to Step 2 | System OK |
