Pinpoint Test A: Speed Control Is Inoperative

A1 CHECK CIRCUITS 7-PG24 (YE/BU) AND 31S-PG24 (BK/OG) FOR SHORT TO BATTERY

Key in OFF position
Disconnect: Powertrain Control Module (PCM) C175b.
Disconnect: Clockspring C218a.
Key in ON position
Measure the voltage between the PCM C175b-56, circuit 31S-PG24 (BK/OG), harness side and ground; and the PCM C175b-57, circuit 7-PG24 (YE/BU), harness side and ground.

Fig 1: Checking Circuits 7-PG24 (YE/BU) And 31S-PG24 (BK/OG) For Short To Battery
Courtesy of FORD MOTOR CO.
Is any voltage present?

Yes

REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.

GO to A2.

A2 CHECK CIRCUITS 7-PG24 (YE/BU) AND 31S-PG24 (BK/OG) FOR SHORT TO GROUND

Key in OFF position
Measure the resistance between the PCM C175b-56, circuit 31S-PG24 (BK/OG), harness side and ground; and the PCM C175b-57, circuit 7-PG24 (YE/BU), harness side and ground.

Fig 2: Checking Circuits 7-PG24 (YE/BU) And 31S-PG24 (BK/OG) For Short To Ground
Courtesy of FORD MOTOR CO.
Are the resistances greater than 10,000 ohms?

Yes

GO to A3.

REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.

A3 CHECK CIRCUITS 7-PG24 (YE/BU) AND 31S-PG24 (BK/OG) FOR AN OPEN

Measure the resistance between the PCM C175b-56, circuit 31S-PG24 (BK/OG), harness side and clockspring C218a-3, circuit 31S-PG24 (BK/OG), harness side; and the PCM C175b-57, circuit 7-PG24 (YE/BU), harness side and clockspring C218a-4, circuit 7-PG24 (YE/BU), harness side.

Fig 3: Checking Circuits 7-PG24 (YE/BU) And 31S-PG24 (BK/OG) For An Open
Courtesy of FORD MOTOR CO.
Are the resistances less than 5 ohms?

Yes

GO to A4.

REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.

A4 CHECK THE CLOCKSPRING

Remove the driver side air bag. Refer to AIR BAG RESTRAINT SYSTEMS .
Disconnect: Upper Clockspring.
Measure the resistance between the clockspring C218a-3, (component side) and the upper clockspring pin 3, (component side); and measure the resistance between the clockspring C218a-4, (component side) and the upper clockspring pin 4, (component side).

Fig 4: Check The Clockspring
Courtesy of FORD MOTOR CO.
Are the resistances less than 5 ohms?

Yes

GO to A5.

INSTALL a new clockspring. REFER to AIR BAG RESTRAINT SYSTEMS . CLEAR the DTCs. REPEAT the self-test.

A5 CHECK THE HORN SWITCH WIRING HARNESS

Disconnect: Horn Switch Wiring Harness Connector.
Inspect the horn switch wiring harness for shorts, opens or any damage.
Is the horn switch wiring harness OK?

Yes

GO to A6.

REPAIR or INSTALL a new horn switch wiring harness. CLEAR the DTCs. REPEAT the self-test.

A6 CHECK THE SPEED CONTROL SWITCH

Connect: Horn Switch Wiring Harness Connector.

Measure the resistance between the horn switch harness pin 3, circuit 31S-PG24 (BK/OG), harness side and the horn switch harness pin 4, circuit 7-PG24 (YE/BU), harness side while pressing the switches.

SPEED CONTROL SWITCH RESISTANCE VALUES

Speed Control Switch	Resistance Value
Cancel	Between 114 and 126 ohms
SET-	Between 285 and 315 ohms
SET+	Between 570 and 630 ohms
Resume	Between 1,055 and 1,165 ohms
On	Between 2,004 and 2,216 ohms
Off	Less than 5 ohms

Fig 5: Checking Speed Control Switch Resistance

Courtesy of FORD MOTOR CO.

Are the speed control switch resistance values OK?

Yes

GO to A7.

INSTALL a new speed control switch. REFER to SPEED CONTROL SWITCH . CLEAR the DTCs. REPEAT the self-test.

A7 CHECK FOR CORRECT PCM OPERATION

Disconnect all the PCM connectors.
Check for:
- corrosion
- pushed-out pins
Connect all 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 INTAKE AIR, FUEL CHARGING, STARTING & ENGINE . TEST the system for normal operation.

The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. REPEAT the self-test.