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Jeep Wrangler 4.0 1997 - Non start , no coil supply voltage - Fixed #

Posted by Damian Daize on November 9, 2010, 4:36 pm

Year of Manufacture *: 1997
( Optional ) Engine Code or CC: 4.0 litre petrol [erh]

Hi All
Struggling to find wiring diagram to help on this vehicle. Non start , cranks over fine .No supply voltage to ignition coil. Need to know where feed comes from ie through imoboliser or direct from ignition switch ? Quite a few wires on the back of ignition switch. Fuses and relays checked and all seem ok. Have noticed fuel gauge not working ? Srs light and mileometer come on when key turned to igntion on though?
AA has been out to this one and crank sensor been renewed!
Have also tried pulling trouble codes inc self diagnosis flash codes with no joy presuming lost ignition feed.
Any help or thoughts appreciated .
Regards
Damian

Re: Jeep Wrangler . Non Start , No Coil Supply Voltage

Posted by Mark Carter <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on November 9, 2010, 6:56 pm, in reply to "Jeep Wrangler . Non Start , No Coil Supply Voltage"
Mark Carter

Hi Damian, does the vehicle start if you back feed the coil ?

Regards Mark

Modern cars, Its all wizardry and witchcraft

Re: Jeep Wrangler . Non Start , No Coil Supply Voltage

Posted by Jim watson <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT5178' width='330' height='300' border=0 style='border:none;'> on November 10, 2010, 8:33 am, in reply to "Jeep Wrangler . Non Start , No Coil Supply Voltage"

Hi, had a look on Tolerance data but could not find that engine code however on Grand Cherokee of that vintage it is wired from pin 87 of the main relay which also feeds the injectors.

Re: Jeep Wrangler . Non Start , No Coil Supply Voltage

Posted by Damian Daize <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT5217' width='330' height='300' border=0 style='border:none;'> on November 10, 2010, 2:33 pm, in reply to "Re: Jeep Wrangler . Non Start , No Coil Supply Voltage"

Thanks for your interest and help so far,
Still does not fire up if we put 12volts to the coil.
We have done an ECU pin out check using Autodata info and it appears we are losing outputs from ECU
We cannot find main Ign relay to test ,possibly within ECU , immoboliser within ECU ? We have good earths and ignition supply to the ECU and crank signal output. We have found some damage to the casing of the ECU and think it could have been the previously mentioned AA patrol man trying to get inside it,not confident this is the cause though not knowing how the system works !!! We are struggling to find anyone to assist with this problem in getting it checked.New ECU backordered from the States.

Having done some research on this not sure why dash gauges don't work and we have no comms or eml light and all are saying it's the crank sensor.[new one fitted]
Am I missing something?

Regards
Damian

Re: Jeep Wrangler . Non Start , No Coil Supply Voltage

Posted by Dave Harney <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT2603' width='330' height='300' border=0 style='border:none;'> on November 10, 2010, 5:14 pm, in reply to "Re: Jeep Wrangler . Non Start , No Coil Supply Voltage"

Damian,
Don't know if this is the correct diag for you !

Regards
Dave

You can trim a sheeps wool many times, but you can only fleece it once !

Re: Jeep Wrangler . Non Start , No Coil Supply Voltage

Posted by Mark Carter <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on November 11, 2010, 9:31 am, in reply to "Re: Jeep Wrangler . Non Start , No Coil Supply Voltage"
Mark Carter

Hi Damian,
the lack of coil feed appears to be the result of the fault and not the cause.

How many ECU power/earth points have you found and how did you test them?

Regards mark

Modern cars, Its all wizardry and witchcraft

Re: Jeep Wrangler . Non Start , No Coil Supply Voltage

Posted by Damian Daize <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT5217' width='330' height='300' border=0 style='border:none;'> on November 11, 2010, 4:35 pm, in reply to "Re: Jeep Wrangler . Non Start , No Coil Supply Voltage"

HI
We have got ignition feed , 12v supply and good earths to the ecu on the correct pins according to autodata. we have also lost the injector supply voltage plus dash gauges inc MIL light . We have no test info on the immoboliser but it does appear to work when the fob is activated in that the led works when armed and the starter does not engage.
We have tried all the usual guys to have this ecu tested with no joy , dealer part not available any longer inc chks done in the States.
Customer is speaking to family members in the USA hoping to find help. We have found a place out there who say they have an ECU but the feed back and reviews on their company set the alarm bells ringing!!!!!
Regards
Damian

Update

Posted by Damian Daize <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT5217' width='330' height='300' border=0 style='border:none;'> on November 12, 2010, 3:45 pm, in reply to "Re: Jeep Wrangler . Non Start , No Coil Supply Voltage"

We have located a secondhand ECU for this vehicle
Do you guys know of any aftermarket diagnostic machine or platform that can re configure the ECU with the vehicle chassis number and mileage as this is how the immoboliser links up and works or is it a Dealer only solution ?
TIA
Damian

Re: Update

Posted by Mark Carter <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on November 12, 2010, 4:55 pm, in reply to "Update"
Mark Carter

Hi, AFAIK it is dealer only

Regards Mark

Modern cars, Its all wizardry and witchcraft

Re: Update

Posted by Paul Foster <iframe src='https://members4.boardhost.com/ukautotalk/info/user=UKAT2680' width='330' height='300' border=0 style='border:none;'> on November 14, 2010, 5:29 pm, in reply to "Re: Update"
Paul Foster

Hi.

I'm assuming that all the fuses have been checked, including the ones behind the glovebox.

These ECUs very rarely give any problems but it's not impossible.

Have you checked the operation of the ASD relay (in the under bonnet fuse box)? It might also be worth checking the operation of the camshaft sensor (in the distributor) and the (new) CPS. I've seen lots of weird faults caused on Jeeps by the crank sensor and even a new one could be faulty.

just a couple of thoughts.

Paul.

Ne te confundant illegitimi

Fixed #

Posted by Damian Daize on November 16, 2010, 6:25 pm, in reply to "Re: Update"
Message modified by board administrator November 18, 2010, 8:26 am

Hi All
Replacement ECU fixed this one.
Thanks for all your input.
Damian

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