Service 4WD Message

A Service 4WD message or Service Engine Soon message may display on the Driver Information Center of some 2019 Silverado 1500 and Sierra 1500 models. The following DTCs may be set:

  • P1899 (Axle Torque Secondary Signal Message Counter Incorrect), P189A (Four Wheel Drive Range Secondary Signal Message Counter Incorrect), or P2534 (Ignition On/Start Switch Circuit Low Voltage) may be set in the Engine Control Module (ECM)
  • DTC C119B (Front Axle Engagement Feedback Switch Circuit) may be set in the Transfer Case Control Module (TCCM)
  • DTC P0700 (Transmission Control Module Requested MIL Illumination) may be set in the Transmission Control Module (TCM)

 

DTCs P1899 or P189A

If DTC P1899 or P189A are set as current DTCs in the ECM, attempt to shift through all the transfer case ranges using the controls on the left side of the instrument panel. (Fig. 17) If the transfer case will shift through all ranges, clear the DTCs. If the DTCs do not reset, return the vehicle to the customer. The DTCs may be setting falsely and GM Engineering is currently validating a repair procedure.

Fig. 17

 

If the transfer case will not shift through all ranges, clear the DTCs. If the DTCs cannot be cleared or reset immediately, replace the TCCM.

 

DTCs C119B, P0700 or P2534

If the only DTC set in the TCCM is DTC C119B, ask the customer about when the condition occurred. It is possible for the DTC to set when a shift out of 4WD is requested and the ignition is turned off prior to the shift being completed. The DTC would be set the next time the ignition is turned on.

Depending on the actual position of the transfer case and the front axle actuator, the DTC may or may not clear when using a scan tool. If the DTC cannot be cleared, shift the transfer case to another position (for example, if in 2HI, shift to 4HI). Try to clear the DTC again. GM Engineering is currently validating a repair procedure for this condition.

If DTC C119B is set in the TCCM, DTC P0700 is set in the TCM, and DTC P2534 is set in the ECM, check fuse F47UA 5A for a possible open condition. (Fig. 18) If the fuse is open, refer to the appropriate Service Information and Bulletin #18-NA-301.

Fig. 18

 

– Thanks to Steve Schipansky

 

 

RKE Transmitter Pocket Locations on the New Silverado and Sierra
Water Pump and Water Pump Housing Replacements

Comments are closed.