Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: TaffyBoy on June 14, 2012, 04:29:47 PM

Title: Cherokee 2.7 crd in limp mode
Post by: TaffyBoy on June 14, 2012, 04:29:47 PM
Hi all
Got a problem whilst out in the jeep this morning.
Warning light with low coolant level flashed up closely followed by engine management light.
Technician came out and advised that the sensor at  the coolant expansion tank was at fault which probably put the jeep in to limp mode. Detached the sensor and cleared the coolant warning light. The engine management light, however, couldn't be cleared with his software and the vehicle got me back home in limp mode.
Where can I get this code cleared. I live in quite a rural part of North Wales. Nearest jeep dealer is over 2 hours away and the local merc dealership say they might have the software but will not know until the vehicle is hooked up at the cost of £70
Any advice welcome :017:
Title: Re: Cherokee 2.7 crd in limp mode
Post by: Lee5 on June 14, 2012, 09:23:23 PM
The low coolant temp sensor wont chuck up the engine cell light, mine plays up all the time but never has it caused a cel light.

You can check the fault codes by turning on and off the ignition switch 4 times, so dash lights on, turn back on click then dash light back on, you need to do this fastish.

It will then change the mileage on the dash and give the fault codes which will be a p0 number.

Post then up and we can then tell you what could be the problem.

Lee
Title: Re: Cherokee 2.7 crd in limp mode
Post by: TaffyBoy on June 14, 2012, 09:31:05 PM
Thanks for the reply. I'll give that a go tomorrow,
Title: Re: Cherokee 2.7 crd in limp mode
Post by: Bishops Finger on June 14, 2012, 10:42:21 PM
£70 is around right for Jeep diagnistics....sadly.....how far from Shrewsbury are you...?
Title: Re: Cherokee 2.7 crd in limp mode
Post by: jay140285 on June 15, 2012, 08:41:31 AM
You could always buy yourself an ODB2 scanner for about £20 / £30 and reset the system yourself.
Title: Re: Cherokee 2.7 crd in limp mode
Post by: TaffyBoy on June 15, 2012, 12:28:14 PM
Thanks for the replies.
Shrewsbury is 2 hours away and about 5 in limp mode :die:
I'll be going for the OBD scanner I think  :ace:
Let you know what the result is next week I hope.
Great site this is :iagree:
Title: Re: Cherokee 2.7 crd in limp mode
Post by: TaffyBoy on June 15, 2012, 12:54:17 PM
Just got out in between the rain storm and checked the fault code with the advice you gave me with the ignition.
Comes up with PO700 and P1685............... any ideas?
Title: Re: Cherokee 2.7 crd in limp mode
Post by: TaffyBoy on June 15, 2012, 01:02:43 PM
Got some info on this site that the PO700 might be to do with input/output sensors.
On the 2.7 crd merc engine are they easy to fit or are they internal in the transmission box as someone has advised me that  they may be?  :100:
Title: Re: Cherokee 2.7 crd in limp mode
Post by: Mike Pavelin on June 15, 2012, 01:39:33 PM
P1685 is a SKIS invalid key code, As it runs, I would ignore this. P0700 indicates there is a fault stored in the transmission control module. You are unlikely to be able to access this with anything other than a dealer's DRBIII scan tool. Enjoy your 5 hour limp :003:
Title: Re: Cherokee 2.7 crd in limp mode
Post by: TaffyBoy on June 15, 2012, 01:50:40 PM
Thanks for the advice Mike.
I'll not worry about the key issue.
I'll be breaking down on the way to the dealership next week I'm sure :hysterical: so a recovery might be in order :icon_jook:
Or maybe. I was wandering, if fitting a new TCM would rectify the problem and be a cheaper option. I can get a new Mopar one for £75
If it has the correct part number I believe it will not have to be recalibrated at the cost of over £100?
Title: Re: Cherokee 2.7 crd in limp mode
Post by: Mike Pavelin on June 15, 2012, 04:48:45 PM
It's unlikely to be the TCM, but the only codes you will get with most OBDII scanners are engine control related only from the PCM. The P0700 code in the PCM is alerting you that the TCM has logged a trouble code. To get into the TCM read codes you need the correct scanner.
Title: Re: Cherokee 2.7 crd in limp mode
Post by: TaffyBoy on June 17, 2012, 07:45:43 PM
Thanks for the advice.
Looks like a visit to the stealership sometime soon.
Hoping it's not going to be too expensive :die:
Title: Re: Cherokee 2.7 crd in limp mode
Post by: jay140285 on June 17, 2012, 09:22:39 PM
Thanks for the advice.
Looks like a visit to the stealership sometime soon.
Hoping it's not going to be too expensive :die:

Do what my mother inlaw did, getr Jeep to diagnose the problem and quote - Their quote was over £1500.

Get it back home, do some googling and I fixed theirs for £120 as it needed a TCM..

Job done.
Title: Re: Cherokee 2.7 crd in limp mode
Post by: TaffyBoy on July 17, 2012, 07:54:34 PM
 :ace:
Whoopie!!!!!!!!!!!
Got the Jeep back on the road.
Thanks for all the advice on here.
I replaced the TCM and the Jeep's been running fine for over a week now.
Life's great again  :ace:
Title: Re: Cherokee 2.7 crd in limp mode
Post by: jay140285 on July 17, 2012, 08:15:00 PM
Result mate,

Was it plug and play the same as the one I did?