On Board Diagnostics II PCED

1999 PCED On Board Diagnostics II

SECTION 5: Pinpoint Tests

FD: Brake Pedal Position (BPP) Switch

Was the brake pedal applied and released during KOER Self-Test?

Yes	No
For Continental and Town Car: GO to Exterior Lighting, Section 417-01 in the Workshop Manual for further diagnosis of the lighting control module (LCM) system. For Windstar: GO to Exterior Lighting, Section 417-01 in the Workshop Manual for further diagnosis of the Rear Electronic Module (REM). All Others: KEY ON. GO to FD3 .	RERUN KOER Self-Test. APPLY and RELEASE brake pedal.

Was the brake pedal applied during KOEO Self-Test?

Yes	No
RERUN KOEO Self-Test. Avoid applying brake pedal during test.	For Continental and Town Car: GO to Exterior Lighting, Section 417-01 in the Workshop Manual for further diagnosis of the lighting control module (LCM) system. For Windstar: GO to Exterior Lighting, Section 417-01 in the Workshop manual for further diagnosis of the Rear Electronic Module (REM). All others: KEY ON. GO to FD3 .

Do the stoplamps operate normally?

Yes	No
GO to FD4 .	For LS6/LS8: GO to Exterior Lighting, Section 417-01 in the Workshop Manual for further diagnosis of the rear electrical module (REM). For all others: GO to FD5 for stoplamps never on. GO to FD7 for stoplamps always on.

Note: If BPP PID is not accessible, GO to FD10 .

Does the BPP PID cycle ON/OFF?

Yes	No
KEY OFF. Unable to duplicate or identify fault at this time. GO to Pinpoint Test Step Z1 .	KEY OFF. GO to FD10 .

Note: Check the condition of the stoplamp bulbs before starting this test.

Disconnect BPP switch.
Measure B+ input voltage between BPP switch harness connector and chassis ground.

Is voltage greater than 10 volts?

Yes	No
GO to FD6 .	VERIFY integrity of fuse for B+ to brake pedal position switch. If OK, REPAIR open in B+ circuit. If fuse is damaged, check B+ circuit, BPP circuit, stop lamp PWR circuit and any other associated circuits (REFER to Wiring Diagrams) for short to ground. REPAIR as necessary.

Connect digital multimeter test probes to BPP switch terminals at the BPP switch.
Apply brake pedal while monitoring reading.

Is the resistance less than 5.0 ohms?

Yes	No
REPAIR open circuit between BPP switch and stoplamp ground.	REPLACE BPP switch.

Are stoplamps still on?

Yes	No
KEY OFF. GO to FD8 .	VERIFY proper installation of BPP switch. If OK, REPLACE switch.

Are stoplamps still on?

Yes	No
KEY OFF. GO to FD9 .	KEY OFF. REPLACE PCM (refer to Section 2 , Flash EEPROM).

One at a time, disconnect all modules associated with the stoplamp circuit (Refer to Wiring Diagram Manual). After disconnecting each module, turn key on and observe stoplamps. Turn key off. Repeat until each associated module has been disconnected or stoplamps turn off.

Did stoplamps turn off when any of the modules were disconnected?

Yes	No
GO to the Workshop Manual for further diagnosis of appropriate module.	REPAIR short to power in stoplamp circuit.

Note: Refer to the PCM connector pin numbers in the beginning of this Pinpoint Test.

Disconnect PCM.
Measure voltage between BPP circuit at the PCM harness connector and ground while applying and releasing the brake.

Does the voltage cycle?

Yes	No
REPLACE PCM (refer to Section 2 , Flash EEPROM).	REPAIR open in BPP circuit to PCM.