2001jeepgrandcherokee

My jeep will start up and dies 3 seconds latter. RPM's don't move and while I press on the gas pedal I cannot get it to run longer than 3 secs no matter what. Also it is not throwing trouble codes and does not scan.

freegdr

Try this......

Hymie

I have taken a look at the workshop manual and have identified the following as favourite (IMO).

From the workshop manual:-

ENGINE START-UP MODE

The Powertrain Control Module (PCM) receives inputs from a number sensors, including the crankshaft position sensor.

If the PCM does not receive a crankshaft position sensor signal within approximately 3 seconds of cranking the engine, it will shut down the fuel injection system.

Therefore I would take a close look at the wiring to the crankshaft position sensor and if nothing appears amiss – replace it, regardless of the fact that you are not seeing any fault codes reported.

Hymie

If it was 1990, I would say that it was due to a faulty ballast resistor in the ignition circuit. However no such component is fitted to modern vehicles.

But with so much electronics on modern vehicles - such an issue can be very hard to diagnose. Looking at the vehicle’s wiring diagram, there could be any number faults causing the vehicle to shutdown.

I have given my two-penny worth - based on the timing of the engine shutdown - but equally it could be an immobilizer issue, as others have suggested.

Be aware that some OBD scanners are better than others at retrieving fault codes – it could be that that vehicle system is not capturing the fault (code).

Therefore check out the cheapest option(s) first – I would be very reluctant to ask a garage to fix such a fault; where you could find yourself footing a very expensive investigative bill.

Good luck!

Bustedback

Try unlocking the passenger door with the key, it sounds like the ECM is in theft mode. Has any work been done before this problem came about?

2001jeepgrandcherokee

Thanks for all the feedback. I read on a thread that disconnecting the battery can clear the computer. Tried and it worked, I was able to now get my car back home. However now none of guages work, spedometer ect., check engine light is on as well as key sensor light stays on.