ABS SYSTEM INSPECTION/VERIFICATION [YF (2.0L Zetec), AJ (3.0L Duratec)]

id0413008003a0

Inspection/Verification

1. Verify the customer concern by applying the brakes under different conditions.

2. Visually inspect for obvious signs of mechanical and electrical malfunction.

• Mechanical malfunction
- Parking brake cable
- Tire pressure
- Tire size or mismatched tires
• Electrical malfunction
- ABS fuse (25 A)
- ABS fuse (60 A)
- ABS/ASC fuse (5 A)
- Connectors or connections
- Harness routing
- Wire chafing
- Open circuit or short circuit
- Indicator bulb

3. If the cause of malfunction is not detected by visual inspection, connect the WDS or equivalent, and perform DTC inspection.

4. If any DTC related to the malfunction is read, refer to the DTC TABLE and continue malfunction diagnosis. (See DTC Table.)

5. If any DTC related to the malfunction is not read, refer to the "SYMPTOM TROUBLESHOOTING CHART" and continue malfunction diagnosis.

Symptom Troubleshooting Chart

Troubleshooting Item

No.

No detected communication with the ABS CM.
1
ABS warning light does not perform self-diagnosis
2
ABS warning light illuminates continuously
3

No.1 No Detected Communication with the ABS CM

Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT ABS HU/CM TERMINAL O VOLTAGE
Turn the ignition switch off.
Disconnect the ABS connector.
Turn the ignition switch to the ON position.
Measure the voltage between the ABS HU/CM terminal O and ground.
Is the voltage more than 10 V?
Yes
Go to the next step.
No
Repair or replace the malfunctioning circuit.
2
INSPECT ABS HU/CM TERMINAL C AND D FOR OPEN CIRCUIT
Turn the ignition switch off.
Measure the resistance between the ABS HU/CM terminal C and ground, and between the ABS HU/CM terminal D and ground.
Is the resistance less than 5 ohms?
Yes
Diagnose the multiple communication system
No
Repair or replace the malfunctioning circuit. Clear DTCs and repeat the self-test.

No.2 ABS Warning Light Does Not Perform Self-Diagnosis

Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT ABS CM
Turn the ignition switch off.
Disconnect the ABS connector.
Turn the ignition switch to the ON position.
Connect a jumper wire (with 10 A fuse) between the ABS HU/CM terminal H and ground
Does the ABS warning light illuminate?
Yes
Replace the ABS CM.
No
Go to the next step.
2
INSPECT ABS HU/CM TERMINAL H FOR OPEN CIRCUIT
Disconnect the instrument cluster connector.
Measure the resistance between the ABS HU/CM terminal H and the instrument cluster connector.
Is the resistance less than 5 ohms?
Yes
Replace the instrument cluster printed circuit.
No
Repair or replace the malfunctioning circuit.

No.3 ABS Warning Light Illuminates Continuously

Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT ABS CM
Disconnect the ABS connector.
Turn the ignition switch to the ON position.
Does the ABS warning light illuminate?
Yes
Go to the next step.
No
Refer to "ABS Warning Light Does Not Perform Self-Diagnosis" and perform the diagnosis.
2
INSPECT FOR SHORT TO GROUND
Turn the ignition switch off.
At the ABS connector, press the shorting bar.
Does the ABS warning light go out?
Yes
After connecting the ABS connector, replace the ABS CM if the ABS warning light illuminates continuously.
No
Repair or replace the malfunctioning circuit.