C1218

C1218/C1243: Pump Motor Ground Circuit Open, High Resistance or Shorted to Battery/Pump Motor Stalled






CIRCUIT DESCRIPTION
Pump motor is contained within Brake Pressure Modulator Valve (BPMV). Pump motor ground is supplied through terminal E136-3 of EBCM. Battery voltage is supplied to EBCM terminal E136-15 when ignition switch is turned on. EBCM terminals E136-1 and E136-2 are 'hot at all times.'

CONDITIONS FOR SETTING THE DTC
^ DTC C1218 can only be set when ignition key is in "ON" position, pump motor is commanded on, and EBCM detected a short to power or high resistance in pump ground circuit.
^ DTC C1 243 can only be set when ignition key is in "ON" position, pump motor is commanded off just after a run command, and EBCM detected a seized or slowly moving pump motor.

ACTION TAKEN WHEN THE DTC SETS
^ ABS relay opens, removing power from pump motor and solenoids.
^ DTC (C1218 or C1243) is stored.
^ ABS disabled, ABS warning light turns on.

DIAGNOSTIC AIDS
Typical causes of DTC C1218.
^ Poor terminal contact at terminal E136-3.
^ Terminal E136-3 ground circuit shorted to voltage.
^ Terminal E136-3 ground circuit open.
^ Terminal E136-3 ground circuit high resistance to ground. Faulty EBCM.
Typical causes of DTC C1243.
^ Poor terminal contact at terminal E136-3.
^ Terminal E136-3 ground circuit high resistance.
^ Terminal E136-3 ground circuit open.
^ BPVM pump motor malfunction.
^ Faulty EBCM.

INSPECTION

Steps 1-2:

NOTE: Diagnostic flow table must be performed first before using this table.