P1568low severityPowertrain
Speed Control Unable to Hold Speed
on 2000 Ford Thunderbird 4.6L V8 · FWD
What this code means
The cruise control system cannot maintain the set speed. The PCM detects excessive variation between set speed and actual vehicle speed during cruise control operation.
Symptoms
- Cruise control disengages
- Speed surges while cruise is active
- Check Engine Light
Common causes
- Faulty cruise control servo/actuator
- Vacuum leak to cruise control actuator (older models)
- Throttle cable or linkage issue
- Vehicle speed sensor issue
- ETC system fault (drive-by-wire models)
Diagnostic steps
- Test cruise control actuator operation
- Check vacuum supply to servo (if vacuum operated)
- Verify vehicle speed sensor accuracy
- Check for other DTCs related to throttle or speed
Repair notes
Replace cruise control actuator if faulty. Repair vacuum leaks. Address related DTCs.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1