Test Procedure
- AY1 CHECK THE BRAKE PRESSURE SWITCH SIGNAL NOTE: Full brake pedal application may be necessary to correctly operate the brake pressure switch.
- Ignition ON, engine OFF.
- Access the PCM and monitor the BPA PID.
- Monitor the BPA PID while applying and releasing the brake pedal.
Does the BPA PID state change when the brake pedal is fully applied and released?
Yes No Unable to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary. GO to AY2. - AY2 CHECK THE BRAKE PRESSURE SWITCH SIGNAL VOLTAGE NOTE: Full brake pedal application may be necessary to correctly operate the brake pressure switch.
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) PCM Connector, Harness Side (-) BPS - Pin B28 Ground - Fully apply and release the brake pedal while measuring the voltage.
Is voltage greater than 10 volts with the brake pedal released and less than 1 volt with the brake pedal fully applied?
Yes No GO to AY5. GO to AY3. - AY3 CHECK THE BRAKE PRESSURE SWITCH VOLTAGE
- Ignition OFF.
- Brake Pressure Switch connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Brake Pressure Switch Connector, Harness Side (-) BPS - Pin 1 Ground Is the voltage greater than 10 V?
Yes No GO to AY4. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test. - AY4 CHECK THE BRAKE PRESSURE SWITCH NOTE: Full brake pedal application may be necessary to correctly operate the brake pressure switch.
- Ignition OFF.
- Measure the resistance between:
(+) Brake Pressure Switch Connector, Component Side (-) Brake Pressure Switch Connector, Component Side B+ - Pin 2 BPS - Pin 1 - Fully apply and release the brake pedal while measuring the resistance.
Is the resistance less than 5 ohms with the pedal released and greater than 10,000 ohms with the pedal fully applied?
Yes No REPAIR the signal circuit.
CLEAR the DTCs. REPEAT the self-test.INSTALL a new Brake Pressure switch. CLEAR the DTCs. REPEAT the self-test. - AY5 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
Is the concern still present?
Yes No INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.