Faulty or erratic vehicle speed signal (speed sensor or its wiring and connector); Throttle control fault, such as a sticking or dirty throttle body or throttle actuator problem, preventing the set speed being held; Cruise control switch or brake pedal switch fault causing false cancel or set inputs; Wiring damage, corrosion or poor connections in the cruise or speed signal circuits; Engine or transmission problem that stops the car holding speed, such as a misfire, restricted airflow or a slipping or hunting gearbox; Fault inside the powertrain control module or an outdated calibration where the manufacturer has issued a known update.

P1563

Cruise Vehicle Speed Set Speed Difference Too High.

Saturn
Powertrain
Manufacturer code
Low severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
5: AreaVehicle speed, idle control and auxiliary inputs
63: FaultThe specific fault in that area

What it means

On a Saturn, P1563 means the control unit saw the actual vehicle speed drift too far from the speed set for cruise control. The cruise system could not hold the set speed within the expected tolerance, so it logged the fault and will usually cancel or disable cruise. Exact trigger thresholds and the monitoring strategy depend on the model and engine.

Symptoms

Cruise control will not engage or drops out unexpectedly
Vehicle speed surges or hunts when cruise is active
Cruise cancels on hills or when the speed changes
Malfunction indicator lamp or service light may be on
Speedometer reading erratic or inconsistent

Possible causes

Faulty or erratic vehicle speed signal (speed sensor or its wiring and connector)likely
Throttle control fault, such as a sticking or dirty throttle body or throttle actuator problem, preventing the set speed being heldlikely
Cruise control switch or brake pedal switch fault causing false cancel or set inputspossible
Wiring damage, corrosion or poor connections in the cruise or speed signal circuitspossible
Engine or transmission problem that stops the car holding speed, such as a misfire, restricted airflow or a slipping or hunting gearboxpossible
Fault inside the powertrain control module or an outdated calibration where the manufacturer has issued a known updaterare

How to diagnose

Read all stored and pending codes and note the freeze frame data, including vehicle speed and engine load when the fault set
Check for other speed sensor, throttle or transmission codes and deal with those first
Inspect the speed sensor, cruise switch and brake switch wiring and connectors for damage, corrosion or looseness
Compare the scan data vehicle speed with the speedometer and a known true speed on a road test
Check the brake switch and cruise switch inputs change state correctly in live data
Inspect the throttle body for carbon build-up and check throttle position readings are smooth through the full range
Check for engine misfires, air leaks or gearbox slip that could stop the car holding a steady speed
Check for any manufacturer service information or calibration updates relevant to the model and engine

How to fix

Repair or replace the faulty speed sensor or repair its wiring and connectors
Clean or replace the throttle body or throttle actuator as testing shows
Replace a faulty brake switch or cruise control switch
Repair damaged wiring and clean or replace corroded connectors
Correct any underlying engine or transmission fault that prevents steady speed
Update or replace the control module only if testing confirms a fault or a known calibration issue

Can I keep driving?

Low severity

The car is normally safe to drive, but cruise control may not work. Book it in soon, especially if the speedometer is erratic or other warning lights are on.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.