Pinpoint Test B: DTC P1572 Or DTC P1703
Cruise Control
Pinpoint Tests
Pinpoint Test B: DTC P1572 Or DTC P1703
Refer to Wiring Diagram Set 31, Cruise Control for schematic and connector information. Diagrams By Number
Normal Operation
When the brake pedal is applied, the stoplamp switch closes and sends voltage to the PCM to deactivate the cruise control, if engaged.
The cruise control deactivator switch (part of the stoplamp switch) removes the voltage signal to the PCM when the brake pedal is applied firmly and passes the cruise control deactivator switch point. This is a redundant signal to the PCM.
The ABS module monitors brake pressure and also receives the stoplamp switch input from the PCM along the High Speed Controller Area Network (HS-CAN) bus. A fault in the ABS module can disable the cruise control system.
- DTC P1572 (Brake Pedal Switch Circuit) - 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 P1703 (Brake Switch Out of Self-Test Range) - sets when there is an open or short in the deactivator switch circuits or when there is an open or short in the stoplamp circuits.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Cruise control deactivator switch (integral to the stoplamp switch)
- ABS module
- PCM
PINPOINT TEST B: DTC P1572 OR DTC P1703
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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B1 CHECK FOR ABS MODULE DTCs
- Review the recorded DTCs from the ABS module self-test.
- Are any DTCs recorded?
Yes
REFER to Antilock Brakes / Traction Control Systems. REPAIR all ABS module DTCs and RETEST the system.
No
GO to B2.
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B2 CHECK THE OPERATION OF THE STOPLAMPS
- Ignition ON.
- Operate the stoplamps.
- Do the stoplamps operate correctly?
Yes
GO to B3.
No
REFER to Lighting and Horns.
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B3 CHECK THE STOPLAMP SWITCH (BOO AND BPA) PIDs
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PIDs BOO (brake pedal top travel) and BPA (brake pedal bottom travel) while applying and releasing the brake pedal as follows:
- Do the PID values agree with the brake pedal positions?
Yes
GO to B8.
No
For an incorrect BOO PID value, GO to B4.
For an incorrect BPA PID value, GO to B5.
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B4 CHECK THE STOPLAMP SWITCH CIRCUIT FOR VOLTAGE
- Ignition OFF.
- Disconnect: PCM C175b.
- Ignition ON.
- While applying the brake pedal, measure the voltage between the PCM C175b-46, circuit CCB08 (VT/WH), harness side and ground.
- Is the voltage greater than 10 volts with the brake pedal applied?
Yes
GO to B8.
No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
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B5 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Stoplamp Switch C2064.
- Ignition ON.
- Measure the voltage between the stoplamp switch C2064-2, circuit CBB32 (GN/VT), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to B6.
No
VERIFY the Battery Junction Box (BJB) fuse 32 (10A) is OK. If OK, REPAIR the circuit. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. TEST the system for normal operation. Diagrams By Number
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B6 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: PCM C175b.
- Ignition ON.
- Measure the voltage between the stoplamp switch C2064-3, circuit CES09 (VT/OG), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
No
GO to B7.
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B7 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between the stoplamp switch C2064-3, circuit CES09 (VT/OG), harness side and the PCM C175b-47, circuit CES09 (VT/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new stoplamp switch. TEST the system for normal operation.
No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
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B8 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 seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new PCM. REFER to Computers and Control Systems. 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.
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