XJ Will Not Start

[CHEQUER-PLATE CHICK]

I was wondering if anyone could point me in the right direction please. A fellow Jeeper's son just pick himself up a 1999 Petrol XJ. He cant get it to start and doesnt know where to look next. When you try to start it, it turns over but nothing happens. While it is turning over, you do not have any interior light, the dash gauges do not move and there is no power to the radio. There is a symbol on the dash that has a picture of a key with a line through it within a circle. The manual says the immoboliser is armed. The young Jeeper bought the XJ at a good price becuase the owner thought it may be the computer. Could it be the key (he was only given one) or is it likely to be the computer? How should we proceed to clarify this issue. I want to do all I can to help this young Jeeper. Thanks for your help.

[JEEPCHIK]

Sounds like the key needs to be programmed to the car. Definately an immobilizer issue. That symbol will show up on the dash to indicate no communication between key and immobilizer.

[GawdZillA]

Checked fuses?

does sound like a key/immobilizer issue tho, weird that it would turn over tho if it is...

[kj69]

If it were an immobilizer issue id be thinking it would start and run for a few seconds then die ,ive tested my immobilizer using a key that is cut but no transponder in the key and it does exactly that ,starts runs then dies .

The dash light with the key symbol does come on when starting my xj then it disappears after it has started .

[Billnick]

According to 'the book' you have an invalid key. For starters (no pun intended) your local locksmith advertising 'auto' may be able to help to program a new key. They can read the code. Second you need a DRB scan tool to properly diagnose the fault. All of this is covered in the manual you can download.

[CHEQUER-PLATE CHICK]

I will put the scan guage on it and see if any codes come up. What is "the Manual you can download"? Where can I download it? I read on an XJ forum of similar problem and it was a shorted out crank position sensor. I have ordered one for the young Jeeper, and I'll get his dad to change it and see if that helps. I'll give anything a try to help him get it started. Thanks for all your help.

[Cypher]

You can download the factory service manual for your Cherokee from the Great Lakes XJ website: http://www.greatlakesxj.com/tech.html

With my '99 XJ, if you put the key in and turn to ON (but not start) it will beep as it verifys the chip on the key and de-imobilises the engine, this takes about 3 seconds and then the yellow key light goes out. Here's some extracts from the service manual:

The Sentry Key Immobilizer System (SKIS) is
designed to provide passive protection against unauthorized
vehicle use by preventing the engine from
operating while the system is armed. The primary
components of this system are the Sentry Key Immobilizer
Module (SKIM), the Sentry Key transponder,
the SKIS indicator lamp, and the Powertrain Control
Module (PCM).

The SKIM is installed on the steering column near
the ignition lock cylinder. The transponder is located
under the molded rubber cap on the head of the ignition
key. The SKIS indicator lamp is located in the
instrument cluster.

The Sentry Key Immobilizer System (SKIS) indicator
lamp gives an indication when the SKIS is faulty
or when the vehicle has been immobilized due to the
use of an invalid ignition key.

The SKIM sends messages to the instrument cluster
to turn the lamp on for about three seconds when
the ignition switch is turned to the On position as a
bulb test. After completion of the bulb test, the SKIM
sends bus messages to keep the lamp off for a duration
of about one second. Then the SKIM sends messages
to the instrument cluster circuitry to turn the
lamp on or off based upon the results of the SKIS
self-tests. If the SKIS indicator lamp comes on and
stays on after the bulb test, it indicates that the
SKIM has detected a system malfunction and/or that
the SKIS has become inoperative.
If the SKIM detects an invalid key when the ignition
switch is turned to the On position, it sends
messages to the instrument cluster to flash the SKIS
indicator lamp