Test C: Speed Control Does Not Disengage With Brakes Applied

WARNING: This page is about a different car, the 2002 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: After making any repairs, retest system for proper operation.

Depress and release brake pedal, inspect stoplight operation. If stoplights operate correctly, go to next step. If stoplights do not operate correctly, repair as necessary. See EXTERIOR LIGHTS in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
Disconnect speed control servo/actuator harness connector C122. Speed control servo/actuator is located on left side of engine compartment. Measure voltage between ground and speed control servo/actuator harness connector C122 terminal No. 4 (Tan/Light Blue wire). See Figure. Press and release brake pedal. Voltage should be zero volts with brake pedal released, and battery voltage with brake pedal pressed. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7.
Turn ignition switch to LOCK position. Disconnect Brake Pedal Position (BPP) switch harness connector C278. Turn ignition switch to RUN position. Measure voltage between ground and BPP switch harness connector C278 terminal No. 3 (White/Yellow wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair open in White/Yellow wire between central junction box and BPP switch. See WIRING DIAGRAMS .
Turn ignition switch to LOCK position. Disconnect Clutch Pedal Position (CPP) switch harness connector C257 (M/T only). Measure resistance in Red/Light Green wire between BPP switch harness connector C278 terminal No. 2 and CPP switch harness connector C257 terminal No. 3. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Red/Light Green wire between central junction box and CPP switch. See WIRING DIAGRAMS .
Measure resistance in Tan/Light Blue wire between CPP harness connector C257 terminal No. 4 (M/T only) and speed control servo/actuator harness connector C122 terminal No. 4. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Tan/Light Blue wire between CPP switch and speed control servo/actuator. See WIRING DIAGRAMS .
Measure resistance between terminals No. 3 and 4 at CPP switch (component side, M/T only). See Figure. If resistance is 5 ohms or less, replace BPP switch. See BRAKE PEDAL POSITION SWITCH under REMOVAL & INSTALLATION. If resistance is more than 5 ohms, replace CPP switch. See CLUTCH PEDAL POSITION SWITCH under REMOVAL & INSTALLATION.
Disconnect speed control servo/actuator harness connector C122. Measure voltage between ground and speed control servo/actuator harness connector C122 terminal No. 9 (Black/Yellow wire). See Figure. Press and release brake pedal. Voltage should be zero volts with brake pedal pressed, and battery voltage with brake pedal released. If voltage is not as specified, go to next step. If voltage is as specified, replace speed control servo/actuator. See SPEED CONTROL SERVO/ACTUATOR under REMOVAL & INSTALLATION.
Disconnect deactivator switch harness connector C1025. Deactivator switch is located on brake master cylinder. Measure resistance between terminals at deactivator switch (component side). Press and release brake pedal. Resistance should be more than 10 k/ohms with brake pedal pressed, and less than 5 ohms with brake pedal released. If resistance is as specified, go to next step. If resistance is not as specified, replace deactivator switch. See DEACTIVATOR SWITCH under REMOVAL & INSTALLATION.
Measure resistance in Black/Yellow wire between speed control servo/actuator harness connector C122 terminal No. 9 and deactivator switch harness connector C1025. See Figure. If resistance is 5 ohms or less, repair open in Light Green/Red wire between central junction box and deactivator switch. If resistance is more than 5 ohms, repair open in Black/Yellow wire between deactivator switch and speed control servo/actuator. See WIRING DIAGRAMS .