Faulty cruise control switch or on/off switch giving a high or stuck signal; Short to voltage or damaged wiring in the cruise engaged signal circuit; Corroded, loose or pushed-out pins in a connector on the circuit; Faulty brake pedal switch or clutch switch feeding the cruise circuit (depends on model and wiring layout); Fault in the steering wheel control or clockspring wiring (depends on model); Faulty powertrain control module input circuit.

P1554

Cruise Engaged Circuit High Voltage.

Buick
Powertrain
Manufacturer code
Low severity

How this code is built

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

What it means

P1554 on a Buick means the powertrain control module has detected a voltage that is too high in the cruise engaged circuit. This circuit tells the module whether cruise control is switched on and active. The code sets when the signal sits above the expected range, which points to a fault in the wiring, the switch or the module input.

Symptoms

Cruise control will not engage or drops out unexpectedly
Cruise control indicator lamp not working or behaving oddly
Check engine light on
Cruise control works intermittently, often affected by bumps or damp weather
No other noticeable change in how the engine runs

Possible causes

Faulty cruise control switch or on/off switch giving a high or stuck signallikely
Short to voltage or damaged wiring in the cruise engaged signal circuitlikely
Corroded, loose or pushed-out pins in a connector on the circuitpossible
Faulty brake pedal switch or clutch switch feeding the cruise circuit (depends on model and wiring layout)possible
Fault in the steering wheel control or clockspring wiring (depends on model)possible
Faulty powertrain control module input circuitrare

How to diagnose

Read the stored codes and freeze frame data, noting whether the fault is current or intermittent, then check for any other cruise or brake switch codes
Check the cruise control operation and indicator lamp, and note whether the fault changes when switching cruise on and off
Inspect the cruise switch, its wiring and connectors for damage, moisture, corrosion and loose pins
Check the brake and clutch switches, their adjustment and their wiring, as these can affect the cruise circuit on some models
Using the model's wiring diagram, check the signal circuit for a short to voltage and for correct reference voltage with the switch in each position
Wiggle test the harness while watching the live cruise engaged data to find an intermittent fault
Check the circuit for continuity and unwanted resistance, and confirm the module grounds are sound
If wiring and switches test good, check the module input following the manufacturer procedure before suspecting the module

How to fix

Replace the cruise control switch if it gives a stuck or out-of-range signal
Repair or replace damaged wiring that is shorted to voltage
Clean or repair corroded connectors and re-seat or replace any damaged terminals
Replace or adjust a faulty brake or clutch pedal switch where it is found to be at fault
Repair or replace the steering wheel control wiring or clockspring if testing proves it faulty
Repair or replace the powertrain control module only after all other causes are ruled out

Can I keep driving?

Low severity

The car is normally fine to drive as the main loss is cruise control. Book it in for diagnosis, and check that the brake lights work correctly if a brake switch is suspected.

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