Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The RPS 5-volt reference circuit, RPS low reference circuit, and RPS sensor signal circuits should be checked for shorts to ground, shorts to voltage, and opens or high resistance.
- With the ignition on check the RPS 5-volt reference signal on the RPS connector pin 8 with the connector disconnected using a DMM.
- The DMM should indicate 4.8-5.2 volts, if the voltage is low check for an open or high resistance or short to ground. If the voltage indicates the voltage is over the specification check for a short to voltage. If the circuit checks good replace the transfer case control module, program, and complete the motor learn procedure. If the circuit checks good with the RPS disconnected, connect the RPS and see if the DTC still show as current. If it does proceed to the next step.
- With the transfer case shift control module connector X1 and X2 disconnected and the RPS disconnected check the RPS signal circuit and the RPS low reference circuits for shorts to ground, high resistance, or shorts to voltage.
- If a shorting condition has been found then repair the circuits as necessary. If nothing is found in circuit testing then replace the RPS, and perform the motor learn procedure.