Fault code P1624 – a step-by-step guide to diagnosing and fixing it

The meaning of error code P1624 – Anti Theft System

P1624: Causes, signs and repairs

Error code P1624 is displayed and the check engine light is on - what does this mean?

The DTC P1624 is recognized by the OBD system when there is a problem with the engine control unit communication or internal processing. This manufacturer-specific trouble code mainly concerns the electronic control unit and can have different meanings for different vehicle brands. In GM vehicles, P1624 often stands for "Engine Control Module (ECM) Internal Performance".

What causes can this error code have?

Defective engine control module (ECM/PCM)
Corroded or damaged plug connections on the control unit
Voltage problems in the vehicle electrics
Defective ground or power supply connections
Software error in the control unit
Overheating of the engine control unit
Electromagnetic interference
Damaged cable connections to the ECM

What symptoms occur in parallel with fault code P1624?

Starting problems: The vehicle is difficult or impossible to start
Engine running unsteadiness: Irregular idling and jerky engine running
Power loss: Reduced engine power and poor acceleration
Exhaust problems: Increased emission levels and black smoke
Electronic failures: Other error codes and malfunctions of various systems
Emergency running program: Engine only runs in restricted mode

How to fix the problem of fault code P1624?

Repairing fault code P1624 requires a systematic approach, as it is a complex electronic problem.
Check and clean all plug connections on the engine control unit and ensure that the contacts are tight
Measuring the power supply to the ECM and repairing defective power supply lines or fuses
Checking and repairing the ECM's earth connections and removing corrosion
Software update or reprogramming of the engine control unit by a specialist workshop
Replacement of the defective engine control unit with a new or overhauled unit
Checking the entire wiring harness area around the ECM and repairing damaged cables

FAQ - Frequently asked questions about DTC P1624

Can I continue driving with fault code P1624?

Continuing to drive with the code P1624 is not recommended, as this is a serious fault in the engine control unit. This can lead to further damage to the engine or other electronic components.

How much does it cost to repair error code P1624?

The repair costs vary greatly depending on the cause. Simple repairs such as plug connections cost 50-150 euros, while replacing the engine control unit can cost 800-2500 euros.

Is error code P1624 the same for all vehicle brands?

No, P1624 is a manufacturer-specific EOBD code and can have different meanings for different brands. At GM, it stands for ECM-internal problems, while the definition may differ for other manufacturers.

Can I repair fault code P1624 myself?

You can carry out basic checks such as plug connections and fuses yourself. For more complex repairs to the control unit, however, you should visit a specialist workshop.

How long does it take to diagnose error code P1624?

A professional diagnosis usually takes 1-2 hours, as extensive tests of the electronic systems and connections are required.

Does error code P1624 return after the repair?

If the repair has been carried out correctly, the fault code should not return. If it does, this indicates an incomplete diagnosis or an additional problem.

Vehicles in which error code P1624 occurs most frequently

Error code P1624 is a manufacturer-specific DTC code that mainly signals problems with the engine control unit and can occur with various electronic faults, but is most common in the following vehicles:

General Motors: Chevrolet Silverado, GMC Sierra, Cadillac Escalade, Chevrolet Tahoe (2003-2014)
Buick: LeSabre, Park Avenue, Regal, Century (2000-2008)
Oldsmobile: Aurora, Intrigue, Alero (1999-2004)
Pontiac: Grand Prix, Bonneville, Grand Am (2000-2009)
Saturn: Vue, Ion, L-Series (2002-2010)

If the code P1624 occurs in your vehicle, it is important to act quickly, as problems with the engine control unit can lead to costly consequential damage. A professional diagnosis is usually essential, as the causes can be varied and require special diagnostic equipment. Do not hesitate to visit a qualified workshop to prevent further damage and ensure driving safety.

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