Jeff Crowley

Ladies & Gents just had the dreaded immobilizer control unit failure. C4S with 105,000 miles original owner. I suggest everyone set aside $2000 for this pleasure sooner or later.

PRSWILL

Yikes!! Which control box is involved with this?

Jeff Crowley

The immobilizer control unit controls the key entry, alarm and blocks access to start the car. When it fails you cannot start the car at all. There is no way to reset it as the immobilizer control unit stops communicating to the main ECU of the car and everything else. The crazy 10 step process to reset the alarm key code is not even accessable.

Flatbed to dealer & order $1400 part, remove drivers seat replace control unit.

Lorenfb

Those units rarely if ever fail. Most mis-diagnose the problem as there are a number
of system elements besides the immobilizer which will prevent the vehicle from starting.

IainM

What a tease, ok ill bite
3: l& r door switches @ frunck switch?

Jeff Crowley

One easy way to tell the control unit has failed is the warning light for immobilizer in clock will not illuminate.

Lorenfb

Not really. How about the following?

1. bad blub
2. bad wiring to bulb
3. bad ignition switch (rear part)
4. bad connections in clock where bulb is located
5. bad immobilizer wiring

nine9six

Not exactly...I had a ground short in my frunk light that kept the immobilizer light from illuminating. The interior lights, engine bay light, glove box light, frunk light, and immobilizer light, are on the same circuit.

This gave me fits tracking things down...but I eventually got there!