97 XJ Shutting Down

[LuluBelle]

hard to read those codes did you use the key turning thing to get the codes? get a cheap obd2 reader off ebay
____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[Jonny Jeep]

Running only with higher revs being used is often a sign of a weak battery so charging/testing of the battery and cleaning the battery posts and clamps is the first thing I'd recommend. 42 - ASD/fuel relay dropping out could well be the relay not getting enough voltage to maintain the coil. Try swapping both relays if battery tests good and still no start.

[warrenm]

Originally Posted by LuluBelle

hard to read those codes did you use the key turning thing to get the codes? get a cheap obd2 reader off ebay
____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

Elcheapo OBD11 reader shows no codes.

Jonny Jeep ASD & Fuel relays have been replaced, battery is less than 12 months old, but hasn't been load tested. Alternator was replaced earlier this year with a new one. Terminals are clean. ASD/Fuel relays are still connected when the engine shuts down,the injector circuit is shutting the engine down.

[Mudgee hunter]

Yeah, pcm! Auto correct,
Same pcm number as mine I sure.
Text or call. Might be able to take a run out there.

[warrenm]

I've done a PCM reset & now starts/runs. I'll take for a run tomorrow, see how it goes. Fingers crossed.

[LuluBelle]

what did you do? disconnect the battery and touch the cables for a bit? ..... good to hear its running
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[warrenm]

Originally Posted by LuluBelle

what did you do? disconnect the battery and touch the cables for a bit? ..... good to hear its running
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

Jeep Electronic Control Unit Reset

When installing new power or performance accessories how does the computer for the Jeep know that it has a new accessory? Most of the time the computer does not. The computer would need to be reset to take full potential of the performance accessories you have added.

The Electronic Control Module, or ECU as its commonly called, stores the information for your vehicle and your driving habits in its memory. The memory is maintaned by a series of capacitors that hold a charge and maintain power for the ECU when the vehicle is turned off. The following procedure will allow you to reset the memory and allow the computer to 're-learn' how to drive by adjusting to the drivers habits and the vehicles modifications.


1. Disconnect the battery by removing the positive battery cable. Remember, the positive battery cable.

2. Ground the positive cable to the negative cable for 30 seconds to erase the electric charge in the capacitors.

3. Reconnect the positive cable to the battery.

4. Turn the key to on but do not start.

5. Turn the headlights on.

6. Turn the headlights off.

7. Turn the key off.


The ECU has now been reset to its factory settings. For the next 50 warm-up periods the ECU will re-learn the engine and driving habits for your driving conditions and the newly installed parts.