Ford F150 Pickup. Instruction — part 347

Fig. 4: Anti-Lock Control Special Tools (2 Of 2)
Courtesy of FORD MOTOR CO.

PRINCIPLES OF OPERATION

The ABS control module receives wheel speed readings from both front wheel speed sensors and the rear
differential speed sensor, and processes this information to determine if an ABS event is necessary. The wheel
speed sensor electrically senses each tooth of the ABS sensor indicators as it passes through the wheel speed

2003 Ford Pickup F150

2003 BRAKES Anti-Lock Control - 4-Wheel - F150 Pickup

sensor's magnetic field.

The ABS control module continuously monitors and compares the rotational speed of each wheel speed sensor
indicator and, when it detects an impending wheel lock, modulates brake pressure to the appropriate brake
caliper(s). This is accomplished by triggering the Hydraulic Control Unit (HCU) to open and close the
appropriate solenoid valves. Once the affected wheel returns to normal speed, the ABS control module returns
the solenoid valves to their normal position, and normal (base) braking resumes.

The ABS control module is self-monitoring. When the ignition switch is turned to the RUN position, the ABS
control module will do a preliminary electrical check, and at approximately 20 km/h (12 MPH), the pump motor
is turned on for approximately one-half second. Any malfunction of the ABS system will cause the ABS to shut
off; normal power assisted braking, however, remains.

INSPECTION & VERIFICATION - SCAN TOOL COMMUNICATIONS CHECK

1. Verify the customer concern by carrying out the Drive Cycle Test.

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

Visual Inspection Chart

Fig. 5: Visual Inspection Chart
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

2003 BRAKES Anti-Lock Control - 4-Wheel - F150 Pickup

3. If the fault is not visually evident, connect the scan tool to the Data Link Connector (DLC) located

beneath the instrument panel and select the vehicle to be tested from the scan tool menu. If the scan tool
does not communicate with the vehicle:

z

check that the program card is correctly installed.

z

check the connections to the vehicle.

z

check the ignition switch position.

4. If the scan tool still does not communicate with the vehicle, refer to the scan tool instruction.

5. Perform the DATA LINK DIAGNOSTIC TEST using the scan tool. If the scan tool responds with:

z

CKT914, CKT915, or CKT70 = ALL MODULES NO RESPONSE/NOT EQUIPPED, go to
MODULE COMMUNICATIONS NETWORK to diagnose network concern.

z

NO RESPONSE/NOT EQUIPPED for the ABS control module, go to PINPOINT TEST A .

z

SYSTEM PASSED for the ABS control module, retrieve and record the continuous Diagnostic
Trouble Codes (DTCs), erase the continuous DTCs and perform self-test diagnostics for the ABS
control module.

6. If the DTCs retrieved are related to the concern, go to ABS CONTROL MODULE DIAGNOSTIC

TROUBLE CODE (DTC) INDEX to continue diagnostics.

7. If no DTCs related to the concern are retrieved, proceed to SYMPTOM CHART to continue diagnostics.

INSPECTION & VERIFICATION - DRIVE CYCLE TEST

The drive cycle test can be used as a system evaluation test, repair verification test, or during diagnosis (for
intermittent concerns).

For system evaluation, the customer may only have a general concern about the way the vehicle is braking.
There may not be a clear system concern to troubleshoot. This test is designed to produce common system
concern symptoms. Once a symptom is found, a symptom troubleshooting procedure can be followed to repair
the vehicle.

Always use this test after vehicle repairs because the anti-lock brake control module is unable to detect some
system concerns unless the vehicle is driven under specific conditions. After completing the drive cycle test,
carry out the self-test using the scan tool.

1. While driving the vehicle approximately 16 km/h (10 MPH), depress the brake pedal hard enough to lock

all four wheels.

2. Does one wheel lock consistently?

z

If yes and the Yellow ABS warning indicator is not illuminated, proceed to the SYMPTOM
CHART .

z

If yes and the Yellow ABS warning indicator is illuminated, retrieve and document DTCs. Proceed

NOTE:

Wetting down the area where the stops are to be performed will aid in this test.

NOTE:

An assistant should be used to monitor the wheels during the ABS stop.
Momentary lockup is permissible.

2003 Ford Pickup F150

2003 BRAKES Anti-Lock Control - 4-Wheel - F150 Pickup

to ABS CONTROL MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX .

3. While driving the vehicle approximately 32 km/h (20 MPH), carry out a light to medium (normal traffic)

stop.

4. Does the pump motor turn on and are brake pedal pulsations felt at any time during the stop?

z

If yes and the Yellow ABS warning indicator is not illuminated, proceed to the SYMPTOM
CHART .

z

If yes and the Yellow ABS indicator does illuminate, retrieve and document DTCs. Proceed to
ABS CONTROL MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX .

5. Clear continuous DTCs.

6. Start the vehicle and shift transmission into low gear.

7. Allow the vehicle to creep forward at idle for at least 45 seconds.

8. Does the Yellow ABS indicator illuminate

z

If yes, retrieve and document DTCs. Proceed to ABS CONTROL MODULE DIAGNOSTIC
TROUBLE CODE (DTC) INDEX

9. Slowly accelerate to 40 km/h (25 MPH). Let at least 45 seconds elapse before reaching 40 km/h (25

MPH).

10. Does the Yellow ABS warning indicator illuminate?

z

If yes, retrieve and document DTCs. Proceed to ABS CONTROL MODULE DIAGNOSTIC
TROUBLE CODE (DTC) INDEX .

11. Has the customer concern been addressed and corrected by the previous actions?

z

If yes, the system is OK.

z

If no, proceed to the SYMPTOM CHART .

ABS CONTROL MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX

ABS MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX

NOTE:

If the pump motor turns on and the vehicle pulls immediately, the front
anti-lock brake sensor opposite the pull should be checked using the ABS
Misfire, ABS Too Sensitive, and ABS Fires On Normal Stop procedure from
the

SYMPTOM CHART

. If the pump motor turns on and the vehicle does

not pull, the rear anti-lock brake sensors should be checked using the
ABS Misfire, ABS Too Sensitive, and ABS Fires On Normal Stop procedure
from the SYMPTOM CHART . If the pump motor does not turn on and the
vehicle pulls immediately, the system should be checked using the
Vehicle Pulls During Braking procedure from the SYMPTOM CHART .

DTC

Description

Source

Action

B1342

ABS Module Internal Failure

ABS

INSTALL a new ABS module. REFER to
ANTI-LOCK BRAKE SYSTEM (ABS)
MODULE .

C1220

Yellow ABS Warning Indicator

ABS

Go To PINPOINT TEST C .

2003 Ford Pickup F150

2003 BRAKES Anti-Lock Control - 4-Wheel - F150 Pickup