Pinpoint Test C: the Speed Control Switches Do Not Operate Correctly
Speed Control
Pinpoint Tests
Pinpoint Test C: The Speed Control Switches Do Not Operate Correctly
Refer to Wiring Diagram Set 31, Speed Control for schematic and connector information. Diagrams By Number
Normal Operation
The PCM sends a signal through circuit 151 (LB/BK) to the speed control switches, which passes through the clockspring. The return signal is sent through circuit 848 (DG/OG) and the clockspring.
- DTC P0579 (Cruise Control Multifunction Input A Circuit Range/Performance) - may set when the speed control switch circuits are open, shorted to voltage or shorted to ground.
- DTC P0581 (Cruise Control Multifunction Input A Circuit High) - sets when the speed control switch circuits are shorted to voltage or open.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Clockspring
- Speed control switch
- PCM
PINPOINT TEST C: THE SPEED CONTROL SWITCHES DO NOT OPERATE CORRECTLY
NOTICE: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.
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C1 CHECK THE SPEED CONTROL SWITCH
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Press each speed control switch button while monitoring the speed control switch PID (SCCS).
- Does the PID value agree with the switch position?
Yes
The system is operating correctly at this time. CLEAR the DTCs. TEST the system for normal operation.
No
If only one switch does not display the correct PID value, INSTALL a new speed control switch. REFER to Speed Control Switch Speed Control Switch. CLEAR the DTCs. TEST the system for normal operation.
Otherwise, GO to C2.
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C2 CHECK THE SPEED CONTROL SWITCH CIRCUITRY FOR A SHORT TO VOLTAGE
- Disconnect: PCM C175b.
- Ignition ON.
- Turn the parking lamps on.
- Measure the voltage between the PCM C175b-19, circuit 151 (LB/BK), harness side and ground; and between the PCM C175b-30, circuit 848 (DG/OG), harness side and ground.
- Is any voltage present?
Yes
TURN the parking lamps off. GO to C3 .
No
TURN the parking lamps off. GO to C6 .
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C3 CHECK CIRCUITS 151 (LB/BK) AND 848 (DG/OG) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: Clockspring C218a.
- Ignition ON.
- Turn the parking lamps on.
- Measure the voltage between the PCM C175b-19, circuit 151 (LB/BK), harness side and ground; and between the PCM C175b-30, circuit 848 (DG/OG), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
No
TURN the parking lamps off. GO to C4.
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C4 CHECK THE CLOCKSPRING FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Connect: Clockspring C218a.
- Remove the driver air bag module.
- Disconnect: Clockspring C218b.
- WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any air bag module when the battery is connected. Failure to follow these instructions may result in serious personal injury in the event of an accidental deployment.
- Connect the battery.
- Ignition ON.
- Turn the parking lamps on.
- Measure the voltage between the PCM C175b-19, circuit 151 (LB/BK), harness side and ground; and between the PCM C175b-30, circuit 848 (DG/OG), harness side and ground.
- Is any voltage present?
Yes
INSTALL a new clockspring. DISCONNECT the battery. INSTALL the driver air bag module. CLEAR the DTCs. REPEAT the self-test.
No
TURN the parking lamps off. GO to C5.
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C5 CHECK THE STEERING WHEEL HARNESS FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Connect: Clockspring C218b.
- Disconnect: Speed Control Switch C203.
- Ignition ON.
- Turn the parking lamps on.
- Measure the voltage between the speed control switch, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. DISCONNECT the battery. INSTALL the driver air bag module. CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new speed control switch. REFER to Speed Control Switch Speed Control Switch. DISCONNECT the battery. INSTALL the driver air bag module. CLEAR the DTCs. REPEAT the self-test.
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C6 CHECK THE SPEED CONTROL SWITCH CIRCUITRY FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the PCM C175b-19, circuit 151 (LB/BK), harness side and ground; and between the PCM C175b-30, circuit 848 (DG/OG), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to C10.
No
GO to C7.
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C7 CHECK THE CLOCKSPRING FOR A SHORT TO GROUND
- Remove the driver air bag module.
- Disconnect: Upper Clockspring C218b.
- Measure the resistance between the PCM C175b-19, circuit 151 (LB/BK), harness side and ground; and between the PCM C175b-30, circuit 848 (DG/OG), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to C9.
No
GO to C8.
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C8 CHECK CIRCUITS 151 (LB/BK) AND 848 (DG/OG) FOR A SHORT TO GROUND
- Disconnect: Clockspring C218a.
- Measure the resistance between the PCM C175b-19, circuit 151 (LB/BK), harness side and ground; and between the PCM C175b-30, circuit 848 (DG/OG), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
INSTALL a new clockspring. INSTALL the driver air bag module. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR the circuit in question. INSTALL the driver air bag module. CLEAR the DTCs. REPEAT the self-test.
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C9 CHECK THE SPEED CONTROL SWITCH FOR A SHORT TO GROUND
- Disconnect: Speed Control Switch C203.
- Measure the resistance between the speed control switchC203-1, circuit 151 (LB/BK), harness side and ground; and between the speed control switchC203-2, circuit 848 (DG/OG), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to C12.
No
REPAIR the circuit in question. INSTALL the driver air bag module. CLEAR the DTCs. REPEAT the self-test.
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C10 CHECK CIRCUITS 151 (LB/BK) AND 848 (DG/OG) FOR AN OPEN
- Disconnect: Clockspring C218a.
- Measure the resistance between the PCM C175b-19, circuit 151 (LB/BK), harness side and the clockspring C218a-13, circuit 151 (LB/BK), harness side.
- Measure the resistance between the PCM C175b-30, circuit 848 (DG/OG), harness side and the clockspring C218a-3, circuit 848 (DG/OG), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to C11.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
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C11 CHECK THE CLOCKSPRING FOR AN OPEN
- Remove the driver air bag module.
- Disconnect: Clockspring C218b.
- Measure the resistance between the clockspring C218b pin 11, component side and the clockspring C218a pin 3, component side.
- Measure the resistance between the clockspring C218b pin 3, component side and the clockspring C218a pin 13, component side.
- Are the resistances less than 5 ohms?
Yes
GO to C13.
No
INSTALL a new clockspring. INSTALL the driver air bag module. CLEAR the DTCs. REPEAT the self-test.
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C12 CHECK THE STEERING WHEEL HARNESS
- Disconnect: Speed Control Switch C203.
- Measure the resistance between the clockspring, harness side and the speed control switch, harness side as follows:
- Are the resistances less than 5 ohms?
Yes
INSTALL a new speed control switch. REFER to Speed Control Switch Speed Control Switch. INSTALL the driver air bag module. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
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C13 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 are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new PCM. 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. CLEAR the DTCs. REPEAT the self-test.
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