Pinpoint Test C: Speed Control Switch Stuck Or Circuit Failure
WARNING: This page is about a different car, the 2008 Ford RV Cutaway, 2008 Ford Econoline, 2008 Ford E450 Super Duty, and 2008 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- D1 CHECK THE SPEED CONTROL SWITCH
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: PCM DataLogger
- Press each speed control switch button while monitoring the SCCS (speed control switch) PID.
- 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 proper PID value, INSTALL a new speed control switch. REFER to Speed Control Switch . CLEAR the DTCs. TEST the system for normal operation.
Other wise Go to C2.
- C2 CHECK THE SPEED CONTROL SWITCH CIRCUITRY FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Disconnect: PCM C175b (Gasoline) or C1381b (Diesel)
- Key in ON position.
- Turn the parking lamps on.
- For gasoline vehicles, 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.
- For diesel vehicles, measure the voltage between the PCM C1381b-31, circuit 151 (LB/BK), harness side and ground; and between the PCM C1381b-24, circuit 848 (DG/OG), harness side and ground.
- Is any voltage present?
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Courtesy of FORD MOTOR CO.
- C3 CHECK CIRCUITS 151 (LB/BK) AND 848 (DG/OG) FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Disconnect: Clockspring C218b
- Key in ON position.
- Turn the parking lamps on.
- For gasoline vehicles, 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.
- For diesel vehicles, measure the voltage between the PCM C1381b-31, circuit 151 (LB/BK), harness side and ground; and between the PCM C1381b-24, circuit 848 (DG/OG), harness side and ground.
- Is any voltage present?
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Courtesy of FORD MOTOR CO.
- YES : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
- NO : TURN the parking lamps off. Go to C4.
- C4 CHECK THE CLOCKSPRING FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Connect: Clockspring C218b
- Remove the driver air bag module. Refer to SUPPLEMENTAL RESTRAINT SYSTEM article.
- Disconnect: Upper Clockspring
- Connect the restraint system diagnostic tool (418-F395) to the upper clockspring air bag connector.
- Connect the battery.
- Key in ON position.
- Turn the parking lamps on.
- For gasoline vehicles, 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.
- For diesel vehicles, measure the voltage between the PCM C1381b-31, circuit 151 (LB/BK), harness side and ground; and between the PCM C1381b-24, circuit 848 (DG/OG), harness side and ground.
- Is any voltage present?
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.- YES : INSTALL a new clockspring. REFER to SUPPLEMENTAL RESTRAINT SYSTEM article. CLEAR the DTCs. REPEAT the self-test.
- NO : INSTALL new speed control switches. REFER to Speed Control Switch . CLEAR the DTCs. REPEAT the self-test.
- C5 CHECK THE SPEED CONTROL SWITCH CIRCUITRY FOR A SHORT TO GROUND
- Key in OFF position.
- For gasoline vehicles, 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.
- For diesel vehicles, measure the resistance between the PCM C1381b-31, circuit 151 (LB/BK), harness side and ground; and between the PCM C1381b-24, circuit 848 (DG/OG), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Courtesy of FORD MOTOR CO.
Courtesy of FORD MOTOR CO.
- C6 CHECK THE CLOCKSPRING FOR A SHORT TO GROUND
- Remove the driver air bag module. Refer to SUPPLEMENTAL RESTRAINT SYSTEM article.
- Disconnect: Upper Clockspring
- Connect the restraint system diagnostic tool (418-F395) to the upper clockspring air bag connector.
- For gasoline vehicles, 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.
- For diesel vehicles, measure the resistance between the PCM C1381b-31, circuit 151 (LB/BK), harness side and ground; and between the PCM C1381b-24, circuit 848 (DG/OG), harness side and ground.
- Are the resistances greater than 10,000 ohms?
- YES : INSTALL new speed control switches. REFER to Speed Control Switch . CLEAR the DTCs. REPEAT the self-test.
- NO : Go to C8.
- C7 CHECK CIRCUITS 151 (LB/BK) AND 848 (DG/OG) FOR A SHORT TO GROUND
- Disconnect: Clockspring C218b
- For gasoline vehicles, 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.
- For diesel vehicles, measure the resistance between the PCM C1381b-31, circuit 151 (LB/BK), harness side and ground; and between the PCM C1381b-24, circuit 848 (DG/OG), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Courtesy of FORD MOTOR CO.
Courtesy of FORD MOTOR CO.
- YES : INSTALL a new clockspring. REFER to SUPPLEMENTAL RESTRAINT SYSTEM article. CLEAR the DTCs. REPEAT the self-test.
- NO : REPAIR the circuit in question. INSTALL the driver air bag module. REFER to SUPPLEMENTAL RESTRAINT SYSTEM article. CLEAR the DTCs. REPEAT the self-test.
- C8 CHECK THE SPEED CONTROL SWITCH CIRCUITRY FOR AN OPEN
- For gasoline vehicles, measure the resistance between the PCM C175b-19, circuit 151 (LB/BK), harness side and the PCM C175b-30, circuit 848 (DG/OG), harness side.
- For diesel vehicles, measure the resistance between the PCM C1381b-31, circuit 151 (LB/BK), harness side and the PCM C1381b-24, circuit 848 (DG/OG), harness side.
- Is the resistance between 4,270 and 4,353 ohms?
- C9 CHECK CIRCUITS 151 (LB/BK) AND 848 (DG/OG) FOR AN OPEN
- Disconnect: Clockspring C218b
- For gasoline vehicles, measure the resistance between the PCM C175b-19, circuit 151 (LB/BK), harness side and the clockspring C218b-6, circuit 151 (LB/BK), harness side; and between the PCM C175b-30, circuit 848 (DG/OG), harness side and the clockspring C218b-2, circuit 848 (DG/OG), harness side.
- For diesel vehicles, measure the resistance between the PCM C1381b-31, circuit 151 (LB/BK), harness side and the clockspring C218b-6, circuit 151 (LB/BK), harness side; and between the PCM C1381b-24, circuit 848 (DG/OG), harness side and the clockspring C218b-2, circuit 848 (DG/OG), harness side.
- Is the resistance less than 5 ohms?
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- YES : Go to C10.
- NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
- C10 CHECK THE CLOCKSPRING
- Remove the driver air bag module. Refer to SUPPLEMENTAL RESTRAINT SYSTEM article.
- Disconnect: Upper Clockspring
- Measure the resistance between the clockspring C218b pin 6, component side and the upper clockspring pin 1, component side; and between the clockspring C218b pin 2, component side and the upper clockspring pin 2, component side.
- Are the resistances less than 5 ohms?
- YES : INSTALL new speed control switches. REFER to Speed Control Switch . TEST the system for normal operation.
- NO : INSTALL a new clockspring. REFER to SUPPLEMENTAL RESTRAINT SYSTEM article. CLEAR the DTCs. REPEAT the self-test.
- C11 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 - GASOLINE ENGINES article or ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE article. 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.