Pinpoint Test B: DTC P0504 OR DTC P1572:01
Cruise Control
Pinpoint Test B: DTC P0504 OR DTC P1572:01
Refer to Wiring Diagram Set 31, Cruise Control for schematic and connector information. Diagrams By Number
Normal Operation
The stoplamp switch and cruise control deactivator switch signals are inputs to the PCM for the cruise control operation.
When the brake pedal is applied, the normally open stoplamp switch closes and applies a voltage signal to the PCM deactivating the cruise control, if engaged.
The cruise control deactivator switch is a normally closed switch that provides a ground signal to the Instrument Panel Cluster (IPC). When the brake pedal is applied, the switch opens and removes the ground signal to the IPC. The IPC sends a network message over the High Speed Controller Area Network (HS-CAN) to the PCM. This is a redundant signal to the PCM.
The PCM receives both signals and compares the inputs to confirm that the correct brake input sequence is received.
- DTC P0504 (Brake Switch A / B Correlation) - sets when the PCM does not sense the correct sequence of the brake pedal input signal from both the cruise control deactivator and stoplamp switches when the brake pedal is pressed and released.
- DTC P1572:01 (Brake Pedal Switch Circuit: General Electrical Failure) - sets when the IPC detects an open in the cruise control deactivator switch signal during the self-test.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Stoplamp switch
- Cruise control deactivator switch
- PCM
- IPC
- Remote Function Actuator (RFA) Module (with Intelligent Access (IA))
PINPOINT TEST B: DTC P0504 OR DTC P1572:01
NOTICE: 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 operate correctly?
Yes
GO to B2.
No
REFER to Exterior Lighting Testing and Inspection to continue diagnosis of the stoplamps.
-------------------------------------------------
B2 MONITOR THE BRAKE PEDAL PIDs
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PIDs (BOO1) (stoplamp switch) and (BOO2) (cruise control deactivator switch) while applying and releasing the brake pedal as follows:
- Do the PID values agree with the brake pedal position?
Yes
For DTC P0504 GO to B11.
For P1572:01 GO to B10.
No
For an incorrect BOO1 PID value, GO to B3.
If the BOO2 PID value always reads OFF, GO to B4.
If the BOO2 PID value always reads ON, GO to B7.
-------------------------------------------------
B3 CHECK THE STOPLAMP SWITCH CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: PCM C175B.
- Ignition ON.
- While applying the brake pedal, measure the voltage between the PCM C175B-2, circuit CCA26 (BU/GY), harness side and ground.
- Is the voltage greater than 10 volts with the brake pedal applied and 0 volts with the brake pedal released?
Yes
GO to B10.
No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
-------------------------------------------------
B4 MONITOR THE CRUISE CONTROL DEACTIVATOR SWITCH PID
- Ignition OFF.
- Disconnect: Cruise Control Deactivator Switch C278.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PID (BOO2).
- Does the B002 PID read ON?
Yes
INSTALL a new cruise control deactivator switch. REFER to Cruise Control Deactivator Switch Cruise Control Deactivator Switch. CLEAR the DTCs. TEST the system for normal operation.
No
If equipped with IA, GO to B5.
Otherwise, GO to B6
-------------------------------------------------
B5 THE RFA MODULE FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: RFA Module C3503B.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PID (BOO2).
- Does the B002 PID read ON?
Yes
INSTALL a new RFA Module. REFER to Multifunction Electronic Modules Service and Repair. CLEAR the DTCs. TEST the system for normal operation.
No
GO to B6.
-------------------------------------------------
B6 CHECK THE CRUISE CONTROL DEACTIVATOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: IPC C220.
- Measure the resistance between the cruise control deactivator switch C278-2, circuit CCA29 (GN/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B10.
No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
-------------------------------------------------
B7 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH FOR AN OPEN
- Ignition OFF.
- Disconnect: Cruise Control Deactivator Switch C278.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- CONNECT a fused jumper wire between the cruise control deactivator switch C278-2, circuit CCA29 (GN/BU), harness side and the cruise control deactivator switch C278-1, circuit GD187 (BK/GN), harness side, while monitoring the PCM PID (BOO2).
- Does the BOO2 PID read OFF?
Yes
REMOVE the jumper wire. INSTALL a new cruise control deactivator switch. REFER to Cruise Control Deactivator Switch Cruise Control Deactivator Switch. CLEAR the DTCs. TEST the system for normal operation.
No
REMOVE the jumper wire. GO to B8.
-------------------------------------------------
B8 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between the cruise control deactivator switch C278-1, circuit GD187 (BK/GN), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to B9.
No
REPAIR the circuit for an open. CLEAR the DTCs. TEST the system for normal operation.
-------------------------------------------------
B9 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH INPUT TO THE IPC FOR AN OPEN
- Disconnect: IPC C220.
- Measure the resistance between the cruise control deactivator switch C278-2, circuit CCA29 (GN/BU), harness side and the IPC C220-29, circuit CCA29 (GN/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B10.
No
REPAIR the circuit for an open. CLEAR the DTCs. TEST the system for normal operation.
-------------------------------------------------
B10 CHECK FOR CORRECT IPC OPERATION
- Connect: All Disconnected Connectors.
- Disconnect all the IPC connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the IPC 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 IPC. REFER to Instrumentation, Message Center, and Warning Chimes Service and Repair. 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.
-------------------------------------------------
B11 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PCM connectors and make sure they are seated 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 Service and Repair.
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.
-------------------------------------------------