SpaceT

My sentry light stays on after failed attempts to start engine. Replaced Crankshaft Position Sensor even though I am getting zero voltage to it from the ECM. I get gas but no spark, fuses good and autoscanner can not communicate to ECM. If ECM is bad how can I verify?

jeepfreak82

Usually only have to lock and unlock the door with the key... The module that controls that is usually seperate from the computer and is mainly intended as an anti-theft unit

jag

You have to check the module

This should help
www.scribd.com/.../Jeep-XJ-2000-08qa-Vehicle-Theft-Security-Systems

ol"blue

Links not working.

jag

Sorry
Just put it your search engine and it will come up

Chances are he is going to have to take it to the dealer so they can scan it with their overpriced drb, but it will show you a way of testing it your self with a volt meter. I would just be carefull not to f anything up.

ol"blue

Check and see if the PCM is showing any fault codes.>->Retrieving codes: http://www.wjjeeps.com/faultcodes.htm

mike37

what year is the cherokee

SpaceT

2000 jeep grand cherokee, no fault codes even though the engine light comes on after a few attempts to start. Scanner also cannot communicate with ECM.

Firestorm500

Sounds like it is in anti-theft mode.

The computer is not recognizing the key.

Dealer time.

thesundancekid

if you have a second key try that one if not you might need to get a new key they can come uncoded over the years

mike37

to reset after a failed start with the anti theft system
you need to use a valid key in the ignition turn to on then off do not try to start

if that doesn't work try to lock and unlock the door or tailgate