PINPOINT TEST B: DTC P0504:00, P0572:00, P0573:00 Or P1703:00

WARNING: This page is about a different car, the 2012 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

B1 CHECK THE OPERATION OF THE STOPLAMPS
- Ignition ON.
- Operate the stoplamps.
- Do the stoplamps and high mounted stoplamp operate correctly?
  - YES : GO to B2.
  - No : REFER to EXTERIOR LIGHTING , to continue diagnosis of the stoplamps.

B2 CHECK THE STOPLAMP SWITCH (BOO1) AND CRUISE CONTROL DEACTIVATOR SWITCH (BOO2) PIDs

Enter the following diagnostic mode on the scan tool: PCM DataLogger.

Monitor the PCM PIDs BOO1 (stoplamp input) and BOO2 (cruise control deactivator switch) while applying and releasing the brake pedal as follows:

Brake Pedal Position	BOO1 PID	BOO2 PID
Released	Off	Off
Applied lightly	On	Off
Applied firmly	On	On

Do the PID values agree with the brake pedal position?
- YES : GO to B7.
- No : For an incorrect BOO1 PID value, GO to B3.
  For an incorrect BOO2 PID value (3.5L engine), GO to B8.
  
  For an incorrect BOO2 PID value (3.7L, 5.0L and 6.2L engines), GO to B4.

B3 CHECK THE STOPLAMP SWITCH CIRCUIT FOR VOLTAGE
- Ignition OFF.
- Disconnect: PCM C1551B (3.5L), C175B (3.7L) or PCM C1381B (5.0L/6.2L).
- Ignition ON.
- For 3.5L engine, while applying the brake pedal, measure the voltage between the PCM C1551B-66, circuit CCB08 (VT/WH), harness side and ground.
  
  Fig 1: Measuring Voltage Between PCM C1551B-66, Circuit CCB08 (VT/WH), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- For 3.7L, 5.0L and 6.2L engines, while applying the brake pedal, measure the voltage between the PCM C175B-13 (3.7L) or C1381B-13 (5.0L/6.2L), circuit CCB08 (VT/WH), harness side and ground.
  
  Fig 2: Measuring Voltage Between PCM C175B-13 (3.7L) Or C1381B-13 (5.0L/6.2L), Circuit CCB08 (VT/WH), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts with the brake pedal applied?
  - YES : GO to B12.
  - No : REPAIR the circuit for an open. CLEAR the DTCs. REPEAT the self-test.
B4 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH FOR CORRECT OPERATION (3.7L, 5.0L and 6.2L)
- Disconnect: PCM C175B (3.7L) or PCM C1381B (5.0L/6.2L).
- While firmly applying and releasing the brake pedal, measure the resistance between the PCM C175B-46 (3.7L) or C1381B-46 (5.0L/6.2L), circuit CES09 (VT/OG), harness side and ground.
  
  Fig 3: Measuring Resistance Between PCM C175B-46 (3.7L) Or C1381B-46 (5.0L/6.2L), Circuit CES09 (VT/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms with the brake pedal released, and greater than 10, 000 ohms with the brake pedal firmly applied?
  - YES : GO to B12.
  - No : GO to B5.
B5 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Stoplamp Switch C278.
- Measure the resistance between the stoplamp switch C278-2, circuit GD120 (BK/GN), harness side and ground.
  
  Fig 4: Measuring Resistance Between Stoplamp Switch C278-2, Circuit GD120 (BK/GN), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
  - YES : GO to B6.
  - No : REPAIR the circuit for an open. CLEAR the DTCs. TEST the system for normal operation.
B6 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between the stoplamp switch C278-3, circuit CES09 (VT/OG), harness side and ground.
  
  Fig 5: Measuring Resistance Between Stoplamp Switch C278-3, Circuit CES09 (VT/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
  - YES : GO to B7.
  - No : REPAIR the circuit for an open. CLEAR the DTCs. TEST the system for normal operation.
B7 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH SIGNAL CIRCUIT FOR AN OPEN
- Connect a fused jumper wire between the stoplamp switch C278-3, circuit CES09 (VT/OG), harness side and the stoplamp switch C278-2, circuit GD120 (BK/GN), harness side.
  
  Fig 6: Connecting Fused Jumper Wire Between Stoplamp Switch C278-3, Circuit CES09 (VT/OG) And Stoplamp Switch C278-2, Circuit GD120 (BK/GN), Harness Side
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the PCM C175B-46 (3.7L) or C1381B-46 (5.0L/6.2L), circuit CES09 (VT/OG), harness side and ground.
  
  Fig 7: Measuring Resistance Between PCM C175B-46 (3.7L) Or C1381B-46 (5.0L/6.2L), Circuit CES09 (VT/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
  - YES : INSTALL a new stoplamp switch. REFER to EXTERIOR LIGHTING . CLEAR the DTCs. TEST the system for normal operation.
  - No : REPAIR circuit CES09 (VT/OG) for an open. CLEAR the DTCs. TEST the system for normal operation.
B8 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH FOR CORRECT OPERATION (3.5L)
- Ignition OFF.
- Disconnect: PCM C1551B.
- While firmly applying and releasing the brake pedal, measure the resistance between the PCM C1551B-93, circuit CES09 (VT/OG), harness side and the PCM C1551B-7, circuit RE407 (YE/VT), harness side.
  
  Fig 8: Measuring Resistance Between PCM C1551B-93, Circuit CES09 (VT/OG) And PCM C1551B-7, Circuit RE407 (YE/VT), Harness Side
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms with the brake pedal released, and greater than 10, 000 ohms with the brake pedal firmly applied?
  - YES : GO to B9.
  - No : GO to B10.
B9 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: Stoplamp Switch C278.
- Ignition ON.
- Measure the voltage between the PCM C1551B-93, circuit CES09 (VT/OG), harness side and ground; and the PCM C1551B-7, circuit RE407 (YE/VT), harness side and ground.
  
  Fig 9: Checking Cruise Control Deactivator Switch Circuit For Short To Voltage
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
  - YES : REPAIR the circuit in question. CLEAR the DTCs. TEST the system for normal operation.
  - No : GO to B12.
B10 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH SIGNAL CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the PCM C1551B-93, circuit CES09 (VT/OG), harness side and the stoplamp switch C278-3, circuit CES09 (VT/OG) harness side; and the PCM C1551B-93, circuit CES09 (VT/OG), harness side and ground.
  
  Fig 10: Checking Cruise Control Deactivator Switch Signal Circuit For Open Or Short To Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms between the PCM and the stoplamp switch and greater than 10, 000 ohms between the PCM and ground?
  - YES : GO to B11.
  - No : REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
B11 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH SIGNAL RETURN CIRCUIT FOR AN OPEN
- Measure the resistance between the PCM C1551B-7, circuit RE407 (YE/VT), harness side and the stoplamp switch C278-2, circuit RE407 (YE/VT) harness side.
  
  Fig 11: Measuring Resistance Between PCM C1551B-7, Circuit RE407 (YE/VT) And Stoplamp Switch C278-2, Circuit RE407 (YE/VT) Harness Side
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
  - YES : INSTALL a new stoplamp switch. REFER to EXTERIOR LIGHTING . CLEAR the DTCs. TEST the system for normal operation.
  - No : REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
B12 CHECK FOR CORRECT PCM OPERATION
- Connect: All Disconnected Connectors.
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
  - YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS . TEST the system for normal operation.
  - No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.