Is it safe to drive with this code?

In many cases the vehicle may still operate normally, though the risk is that the immobiliser system could prevent starting without warning. If the code is accompanied by starting difficulties or the immobiliser lamp stays on, onward driving may leave you stranded. See our disclaimer for guidance on when to seek professional assistance.

P0648 may affect your MOT result if the malfunction indicator lamp (engine warning light) is illuminated at the time of the test, as dashboard warning lamps are checked during MOT inspection - see our MOT disclaimer for details.

Roughly how much does it cost to fix?

Costs vary considerably depending on the root cause. A key fob battery is typically low two-figure, whilst replacing a faulty lamp bulb or repairing simple wiring might fall into the low three-figure range at an independent garage. However, if a body control module or engine control module requires replacement and reprogramming, costs can climb into the mid to high three-figure bracket, or even four-figure territory at a main dealer. Diagnostics alone often cost between one and two hours of labour depending on the complexity of the fault.

Can I just clear the code and carry on?

Clearing the code without addressing the underlying fault typically results in it returning, often quite quickly. If the issue involves a flat key battery or intermittent connection, the code may stay away temporarily, but proper diagnosis is recommended to avoid potential starting failures.

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← All fault codes | Immobiliser

P0648

Powertrain

Immobilizer Lamp Control Circuit

The engine control module has detected an issue with the electrical circuit that operates the immobiliser warning lamp on your dashboard.

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ⓘ Information only. This page provides general educational information about fault code P0648. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.

Recommended next steps

Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.

What does P0648 mean?

P0648 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Immobilizer Lamp Control Circuit.

This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.

About Immobiliser codes

Immobiliser codes relate to the security system that prevents the engine starting without a valid key signal. Faults can mean the engine cranks but won't fire, or the key isn't being recognised. These usually need manufacturer-specific diagnostics to resolve.

P0648 is one of 64 codes in this category. Browse all Immobiliser codes →

What we know about P0648 specifically

We record the SAE J2012 standardised definition and the system this code belongs to, but we have not yet published detailed driver-reported symptoms, common causes, or step-by-step diagnostic guidance for P0648.

Rather than invent that information by generating generic content from a template, we leave it out. For specific guidance, the most reliable sources are:

•your vehicle's own service manual or manufacturer-specific technical bulletins
•a qualified mechanic with a manufacturer-level diagnostic tool
•a marque specialist familiar with your make and model

Codes nearby

Codes adjacent to P0648 in the P-code series. Many fault codes appear together with their neighbours because they relate to the same circuit or component.

P0645 A/C Clutch Relay Control Circuit

P0646 A/C Clutch Relay Control Circuit Low

P0647 A/C Clutch Relay Control Circuit High

P0649 Speed Control Lamp Control Circuit

P064A Fuel Pump Control Module

P064B PTO Control Module

Other Immobiliser codes

Other fault codes in the same system as P0648. The ones with detailed guides have plain-English explanations, symptoms, causes, and diagnostic steps.

B1105

Tailgate Reference Voltage Fault

B1213

An Open in the Rear Evaporator Temperature Sensor Circuit

B13D4

Immobilizer Transmitter Less Than Minimum Programmed-No Sub Type Information

B1600

PATS Ignition Key Transponder Signal Not Received

B1601

Left Solar Sensor Circuit Low

B1A24

Key ID not registered

Spotted an issue or have something to add? Mechanics, technicians, and drivers who have first-hand experience with P0648 can submit a correction or expansion. We review every submission before publishing, mechanic submissions are prioritised.

Information only, not professional advice

The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →

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