Pinpoint Test F: DTCs C1287 and C1446: Testing
- F1 CHECK THE PCM AND ABS MODULE DTCS
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Network Test - All Continuous Memory Diagnostic Trouble Codes (CMDTCs). Record and review the PCM and the ABS module DTCs. Diagnose all PCM DTCs before diagnosing any ABS module DTCs.
- Are any PCM DTCs present?
Yes : REFER to INTRODUCTION -- GASOLINE MODELS or INTRODUCTION -- 6.0L DIESEL articles.
No : If any ABS module communication DTCs (U-Codes) are present, REPAIR them before diagnosing C1287 or C1446.
If ABS module DTC C1446 is present, GO to F2 .
If ABS module DTC C1287 is present, GO to F9 .
For all other ABS module DTCs, GO to the Anti-Lock Brake System (ABS) Module Diagnostic Trouble Code (DTC) Index. See ANTI-LOCK BRAKE SYSTEM (ABS) DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
- F2 CHECK THE BRAKE FLUID LEVEL
- Check the brake fluid level in the master cylinder.
- Is the brake fluid at an acceptable level?
Yes : GO to F3.
No : REFER to BRAKE SYSTEM - GENERAL INFORMATION - F250-F550 to continue diagnosis of the base brake system.
- F3 CHECK THE BRAKE FLUID LEVEL SWITCH ELECTRICAL CONNECTOR CONDITION
- Ignition OFF.
- Disconnect: Brake Fluid Level Switch C124.
- Check the connector for: corrosion, pushed-out pins, spread terminals.
- Is the brake fluid level switch electrical connection OK?
Yes : GO to F4 .
No : REPAIR the connector/wire harness or INSTALL a new connector/wire harness as necessary. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
- F4 ISOLATE THE BRAKE FLUID LEVEL SWITCH
Connect a fused (5A) jumper wire between the brake fluid level switch C124-2, circuit 512 (TN/LG), harness side and the brake fluid level switch C124-3, circuit 531 (DG/YE), harness side.
- Ignition ON.
- Using the scan tool, clear the ABS module DTCs.
- Test drive the vehicle then retrieve and record all ABS module DTCs.
- Did DTC C1287 or C1446 return?
Yes : REMOVE the jumper wire. GO to F5 .
No : REMOVE the jumper wire. INSTALL a new brake master cylinder. REFER to HYDRAULIC BRAKE ACTUATION - F250-F550 . CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
- F5 CHECK THE BRAKE FLUID LEVEL SWITCH RETURN CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Instrument Cluster C220B.
- Measure the resistance between the instrument cluster C220B-14, circuit 512 (TN/LG), harness side and the brake fluid level switch C124-2, circuit 512 (TN/LG), harness side.
- Is the resistance less than 5 ohms?
Yes : GO to F6 .
No : REPAIR circuit 512 (TN/LG). CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
- F6 CHECK BRAKE FLUID LEVEL SWITCH SIGNAL CIRCUIT FOR AN OPEN
- Measure the resistance between the instrument cluster C220B-1, circuit 531 (DG/YE), harness side and the brake fluid level switch C124-3, circuit 531 (DG/YE), harness side.
- Is the resistance less than 5 ohms?
Yes : GO to F7 .
No : REPAIR circuit 531 (DG/YE). CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
- F7 CHECK BRAKE FLUID LEVEL SWITCH SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between the brake fluid level switch C124-3, circuit 531 (DG/YE), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Courtesy of FORD MOTOR CO.
Yes : GO to F8 .
No : REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
- F8 CHECK BRAKE FLUID LEVEL SWITCH RETURN CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between the brake fluid level switch C124-2, circuit 512 (TN/LG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Courtesy of FORD MOTOR CO.
Yes : GO to F9 .
No : REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
- F9 MONITOR THE PCM BRAKE ON/OFF (BOO) PID
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - PCM.
- Monitor the BOO PID, while pressing and releasing the brake pedal.
- Does the PID display ON when the pedal is pressed and OFF when the pedal is released?
Yes : GO to F10 .
No : REFER to STOPLAMPS to diagnose the stoplamp switch.
- F10 MONITOR THE PCM BRAKE PRESSURE APPLIED SWITCH (BPA) PID
- Monitor the BPA PID, while firmly pressing and releasing the brake pedal.
- Does the PID display ON when the pedal is firmly pressed and OFF when the pedal is released?
Yes : GO to F11 .
No : REFER to SPEED CONTROL - F250-F550 to diagnose the speed control deactivator switch.
- F11 MONITOR THE ANTI-LOCK (ABS) MODULE (BOO) PID
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS Module.
- Monitor the BOO PID, while pressing and releasing the brake pedal.
- Does the PID display ON when the pedal is pressed and OFF when the pedal is released?
Yes : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
No : Go to F12.
- F12 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect: ABS Module C135.
- Check the connector for: corrosion, spread terminals, pushed-out pins.
- Connect: ABS Module C135.
- Make sure the connector seats properly, then operate the system and verify the concern is still present.
- Is the concern still present?
Yes : INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . CLEAR the DTCs. REPEAT the self-test.
No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.