Hi Guys,

Am a new member to the XJ8 forum.
My brother has an XJ8 (2000) RHD and it would not start after an 8 mile drive.
I borrowed a laptop with an OBDII reader and it was definitely getting power from the socket but it would not read anything.
A friend also has an XJ8 (1999) and the garage had the same problem with his failing to read.
Any ideas welcomed!

I suspect my brother's is a fuel pump fault. Anyone know the connector pins to check for voltage etc.?

Thanks for any help.

David.

 

The program running on the laptop needs to be using the correct protocol to communicate with the Jag's OBD system. Some programs give you a choice to pick from. I believe the Jag uses ISO 9000, or something like that. Some programs can detect the protocol and automatically switch to it, others you have to know what to set it to. It's hard to believe a garage would not be able to get this to work. OBDII has been a required standard in the USA since 1996.

 

A cheap code reader works great $45 obdii

 

Thanks for the replies.

Have now checked and there is definitely no fuel at the Schrader valve on the injector pipes.

At the top of the tank is what I assume to be the fuel pump & fuel level sensor. Is this correct?

If so it has 4 wires connecting to it with a multiway plug. The wires appear to be (clockwise starting at top right) black/white, red, brown/green, black.
I can only find 10.3 volts going to the red and Black/white pins. removing the relay (no. 4) makes no difference to this supply.
Is this correct?
If correct am I safe to assume the pump has died?
If not correct where do I go next. Have checked relay 4 in the boot and it operates with the ignition correctly. Similarly the fuses appear all ok.

Thanks for reading.

David.

 

The fault was with the crank position sensor.
The ecu had no fault codes recorded.
I reckon the ecu cuts out the fuel pump during cranking to prevent flooding.

Hope this helps the next person with similar symptoms.

 

Glad to hear you sorted your problem, crank sensors are a sod when they fail.

As for the OBD port they are usually in the drivers foot well, underneath the dash by the transmission. (big black plug roughly 2" x 0.5") At least that's were it is on XJ's; and be careful to follow the instructions for when to connect and disconnect as mine went mad (started throwing all sorts of random codes from TCS not available to low brake fluid) and i had to reset the computer (disconnecting the battery for 15 mins did the trick).

But when you use it properly (and that may mean reading the instructions - which as a man I feel must be considered a sign of weakness!!! ) they are a god send, i fixed my misfire problem for about £25 rather than taking it to a specialist.

Good luck and if you really cant find it post again and i'm sure someone else can post a pic.

Alex

 

Hi Alex, can you tell me which obd reader your using, im in the uk also and im looking for one thats compatable with my 1998 xj8,if you dont mind me asking where did you get it and how much ?

 

There is a thread on the General Forum that discusses the readers that work and those that do not. Check here: https://www.jaguarforums.com/forum/s...ad.php?t=33347

The XK8/R connector is directly above the hood release handle in the US. I suspect that is true for both LH or RH cars.

 

Hi ricasso,

My scanner is a 'MemoScanner U480' - got it from ebay for ~£25 plus postage.

http://cgi.ebay.co.uk/LATEST-UNIVERS...item19b6744be1

- good starting point, just have a shop around and check what other sites/vendors are offering

But as test point said there is a good section on the forum (if the U480 isn't listed i'll see about adding it as it sure did the job for me [1999 XJR])

Alex

 

Do you mean reader instructions or Jaguar instructions? My XJ8 driver's manual says nothing about the computer other than to take it to a mechanic to read it.

If I had instructions with my reader (don't think I did), they're long gone.

 

He means the instructions for the reader. The Jag manuals will not help. If you can't find your instructions for the OBDII reader, I'm sure you can do a google search and find something. There seems to be a uTube video out there for everything also. On my XJ8 the OBDII plug is right above your right knee (left hand drive) under the dash.