Software Incompatibility with Vehicle Security Control Module

Possible causes

• CommonThe vehicle security control module replaced but never coded to this vehicle
• CommonUsed module fitted from another vehicle - security modules are often locked to their original VIN
• CommonEngine module replaced without re-matching it to the immobiliser
• CommonSoftware update interrupted during programming
• CommonKeys not re-learned after a module change
• PossibleAftermarket alarm or immobiliser interfering with the system

What you might notice

• Engine turns over but will not start
• Immobiliser or key warning light on
• Key not recognised
• Alarm behaving unpredictably
• Fault present since a repair or a key replacement

What to check, in order

1. Do not switch the engine off far from home until this is fixed. A vehicle that starts today may not start again.
2. Keep the spare key and any mechanical key blade with you.
3. Ask what was done. An engine module or immobiliser replacement without re-matching is the usual explanation.
4. If a used module was fitted, check whether it is locked to its original vehicle. Security modules very often are, and some cannot be transferred at all - which makes the cheap second-hand part worthless.
5. Expect proof of ownership to be required. Coding these modules is deliberately restricted, and that is a feature rather than an obstruction.
6. Budget for a franchised dealer or a properly equipped auto-locksmith. A generic tool cannot do this work.