Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: Anonymous on October 14, 2005, 10:44:13 PM

Title: Dead XJ
Post by: Anonymous on October 14, 2005, 10:44:13 PM
A mate has just had a tow bar fitted to a 2000 XJ orvis and since fitting it wont start. Turns over but no life in it.
I am off to the fitters to look at it tomorrow armed with the FSM diag notes, but a quick question, what does the immobiliser stop working? ecu, HT side, fuel pump etc or the whole lot?

cheers
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Post by: UKJeeper on October 14, 2005, 11:11:10 PM
Tow bar? Near the fuel tank? I'd wonder if the fuel pump wiring was OK.
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Post by: Anonymous on October 15, 2005, 07:36:53 AM
good point, will check if its fired up
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Post by: Anonymous on October 15, 2005, 02:02:28 PM
fuel pump is fine, can find anyone with an obd-2 reader to check it but have got a spare CPS we are going to put on now.
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Post by: Woody on October 16, 2005, 04:01:29 PM
Steve

Had a crank position sensor problem on my XJ, the engine will turn over but not fire up.  A good check is to stick some of the spark plug testers in line to see if you are getting a spark, if not it is most probably crank position sensor.  The other possibility is cam position sensor but that is less common than the crank position sensor.  It is worth taking it out before you try getting one.  It took my local dealership 2 attempts to get the right one in stock.  Depending on age of car etc sensors could be 5V or 9V and you need the correct one.

Are you getting any fault codes:

http://jeephorizons.com/phpbb/viewtopic.php?t=2719 (http://jeephorizons.com/phpbb/viewtopic.php?t=2719)
http://www.jeepclub.co.uk/diagnostics.cfm (http://www.jeepclub.co.uk/diagnostics.cfm)

Woody
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Post by: Mike Pavelin on October 16, 2005, 05:52:24 PM
9v round plug, 5v, rectangular plug.
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Post by: Anonymous on October 16, 2005, 09:56:48 PM
more on it, after fannying around a bit more I scoped the CPS and its fine, turned out that a fuse was going (owner swore blind they were all okay and dumb ass me didnt check  :roll: )

Right then, he has recently had a 2 trailer leccy system put on and now when you turn the key to position 3 fuse 24 in the PDC blows, looking at the FSM thats the 02 sensors, will no power to the 02 sensors cause the ignition curcuits not to fire?
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Post by: Mike Pavelin on October 16, 2005, 10:22:41 PM
2000 FSM says PDC fuse 24 is B+ battery feed to PCM. Won't even think about starting without it.
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Post by: Anonymous on October 17, 2005, 08:07:26 AM
weird, thats different to my fsm :?

ANyway it isnt the 02 sensors, I was looking at 2001 fsm, doh.
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Post by: Anonymous on October 17, 2005, 08:09:51 AM
you looking at 8w-10-19 ? Isnt that a diesel model only? I cant seem to find what fuse 24 does on a 2000 XJ :?
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Post by: Mike Pavelin on October 17, 2005, 08:37:25 AM
Yeah, you're right, too late in the day for me.
PDC fuse 24 on a petrol appears as a redundant spare fuse in the FSM if you look in 'power distribution'.
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Post by: Anonymous on October 17, 2005, 09:30:42 AM
same here (or too early) Its fuse 21 thats blowing and the Jeep is a 1999MY although on a 2000 reg.

So its the PCM, injectors and Coil fuse thats going pop. Does the PCM send the signal for the reversing lights? (just wondering if there is a short on the new wiring)
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Post by: Mike Pavelin on October 17, 2005, 11:07:14 AM
Fuse 21 is the fuse between the ASD relay output and the PCM, so it will kill the Jeep. When the ignition is turned on, it puts a feed to the PCM, this griunds the ASD relay, which in turn returns another feed back to the PCM via fuse 21. The reverse lights have their own fuse. Have they fitted a split charging relay system for the trailer?
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Post by: Anonymous on October 17, 2005, 01:06:16 PM
I thouht 21 did the coil and injectors?
Anyway they fitted a split charge twin electric setup, I reckon this is grounded somewhere but it takes a feed straight from the back of the alternator fpr charging and another from the +ve from the battery, just dont see how that would take a fuse out as the leads for it both have inline fuses.

Oh and if you put a 25amp fuse in the engine runs for a few seconds before blowing.
And we have swapped my coil pack over, its not that.  :?:
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Post by: Anonymous on October 17, 2005, 06:38:13 PM
sorted it, he took a 12 volt feed from the back of the alternator, not sure which wire, we removed this and it works fine. My mate is off to negotiate about how much the chap wants to charge for fitting this tow bar now  :axe:

Thanks all
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Post by: Mike Pavelin on October 17, 2005, 07:29:00 PM
The wire to the alternator is the field control wire to the PCM, which it uses to control alternator output, That's why I asked about the split charging, thought they might have done that!