Test M: Set Speed Fluctuates
NOTE:
After any repairs are complete, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM
.
- Ensure engine is properly tuned. Ensure problem does not occur while driving vehicle without speed control activated. If problem occurs only with speed control activated, go to next step. If problem occurs without speed control activated, repair engine as necessary.
- Check for binding or sticking speed control servo/actuator cable, throttle linkage and/or throttle plate. Ensure throttle cable bracket and speed control servo/actuator bracket are not loose. If problem does not exist, go to next step. If problem exists, repair as necessary.
- Test drive vehicle and observe speedometer operation. If speedometer operates properly, go to next step. If speedometer does not operate properly, repair speedometer as necessary. See INSTRUMENT PANELS - SABLE & TAURUS article.
- On Taurus SHO models, go to next step. On all other models, go to step 6 .
- Disconnect speed control servo/actuator harness connector C102. Disconnect ABS control module harness connector C1057. Measure resistance in Gray/Black wire between terminal No. 3 at speed control servo/actuator harness connector C102 and terminal No. 12 at ABS control module harness connector C1057. See Figure and Figure . If resistance is 5 ohms or less, replace speed control servo/actuator. If resistance is greater than 5 ohms, repair open in Gray/Black wire.
- Disconnect speed control servo/actuator harness connector C102. Disconnect vehicle speed sensor harness connector C1043. Measure resistance in Gray/Black wire between terminal No. 3 at speed control servo/actuator connector C102 and vehicle speed sensor harness connector C1043. If resistance is 5 ohms or less, replace speed control servo/actuator. If resistance is greater than 5 ohms, repair open in Gray/Black wire.