Pinpoint Test F: DTC C1127 - DEACTIVATOR Switch Circuit Failure

WARNING: This page is about a different car, the 2004 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

Test Step

F1 CHECK THE SPEED CONTROL ACTUATOR

Key in OFF position.
Disconnect: Speed Control Actuator C122.
Measure the voltage between speed control actuator C122 pin 9, circuit 636 (OG), harness side and ground, while firmly applying and releasing the brake pedal.

Fig 1: Checking Speed Control Actuator
Courtesy of FORD MOTOR CO.
Is the voltage greater than 10 volts with the brake pedal released and zero volts with the brake pedal applied?

Result / Action to Take

Yes

INSTALL a new speed control actuator. REFER to SPEED CONTROL SERVO . REPEAT the self-test.

GO to F2.

Test Step

F2 CHECK CIRCUIT 10 (LG/RD) FOR AN OPEN

Disconnect: Deactivator Switch C277.
Measure the voltage between deactivator switch C277, circuit 10 (LG/RD), harness side and ground.

Fig 2: Checking Circuit 10 (LG/RD) For An Open
Courtesy of FORD MOTOR CO.
Is the voltage greater than 10 volts?

Result / Action to Take

Yes

GO to F3.

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

Test Step

F3 CHECK CIRCUIT 636 (OG) FOR AN OPEN

Measure the resistance between speed control actuator C122 pin 9, circuit 636 (OG), harness side, and deactivator switch C277, circuit 636 (OG), harness side.

Fig 3: Checking Circuit 636 (OG) For An Open
Courtesy of FORD MOTOR CO.
Is the resistance less than 5 ohms?

Result / Action to Take

Yes

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

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