Diagnostic Aids

Thoroughly inspect the MPA switch jumper harness for any condition that may cause an intermittent malfunction. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS .

An intermittent DTC may be difficult to verify since the DTC may take a substantial amount of time to set. If a DTC continues to set intermittently, remove the MPA switch and activate the switch by pressing and releasing the plunger. Ensure the plunger movement is smooth and that the plunger releases readily without sticking. Observe the MPA Switch input on the scan tool to verify that the status changes from Uncharged to Charged every time the switch is pressed. Replace the BPMV if no fault is found in the switch, circuitry or connections. Refer to Brake Pressure Modulator Valve (BPMV) Replacement (w/JL4)  or Brake Pressure Modulator Valve (BPMV) Replacement (w/o JL4)  .