C1073-Abs Motor Control Circuit (340)

C1073-ABS MOTOR CONTROL CIRCUIT (340)

^ When Monitored:
With the ignition on and no system under voltage condition present.
^ Set Condition:
OPEN CIRCUIT If pump motor feedback remains greater than 0.75 volts for more than 50 msec (+/- 5 msec) after monitoring conditions are met, the DTC will set.
LOCKED MOTOR: If the module detects that the motor is spinning at less than 500 r.p.m. after monitoring conditions are met, the DTC will set.
LOW VOLTAGE: The voltage of the supply is monitored every 3 msec. If the voltage is low for 150 msec, the DTC will set.
Possible Causes
- INTERMITTENT ABS MOTOR CONTROL CIRCUIT DTC
- (A107) FUSED B+ CIRCUIT OPEN OR HIGH RESISTANCE
- (Z107) OR (Z923) GROUND CIRCUIT OPEN OR HIGH RESISTANCE
- ANTI-LOCK BRAKE MODULE
Diagnostic Test
1. DTC IS ACTIVE
Turn the ignition on.
With the scan tool, clear DTCs. Turn the ignition off.
Turn the ignition on. With the scan tool, actuate the ABS pump motor.
Did the Pump Motor operate when actuated?
No >Go To 2
Yes >Go To 5

2. (A107) FUSED B+ CIRCUIT OPEN OR HIGH RESISTANCE
Turn the ignition off.
Disconnect the Anti-lock Brake Module harness connector.
NOTE: Check connector - Clean/repair as necessary.
Using a 12-volt test light connected to ground, check the (A107) Fused B+ Circuit.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes >Go To 3
No >Repair the (A107) Fused B+ Circuit for an open circuit or high resistance.
Perform ABS VERIFICATION TEST - VER 1. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > EBC 340

3. (Z107) or (Z923) GROUND CIRCUIT OPEN OR HIGH RESISTANCE
Using a 12-volt test light connected to 12-volts, check the (Z107) and (Z923) Ground circuits.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes >Go To 4
No >Repair the (Z107) or (Z923) Ground Circuit(s) for an open circuit or high resistance.
Perform ABS VERIFICATION TEST - VER 1. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > EBC 340
4. ANTI-LOCK BRAKE MODULE
Turn the ignition off.
Inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
Inspect the related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes >Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > EBC 340
No >If no other problems are found, replace the Anti-lock Brake Module.
Perform ABS VERIFICATION TEST - VER 1. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > EBC 340
5. WIRING HARNESS INSPECTION
Turn the ignition off.
Inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
Inspect the related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes >Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > EBC 340
No >Test Complete.