Sorry been away.
I've had the car ran through diagnostics, and it doesn't pick up a single fault?
The guy who did it said Because of the lack of fault codes it coul be a broken wire into the abs module. Estimated cost of finding wire £200-£500 :-0 does this sound right?

 

Assuming it's an 'analog' speedo like mine, try tapping the plexi with your knuckles while watching the pointer against the end-stop. (No need to be driving it). If the needle bounces ever so slightly from the end stop at least you know the mechanism isn't jammed.

Leedsman.

 

nope, a load of bollocks.

Speedo is driven by data message from (BCM) Body Control Module, which in turn is receives a data message from the EATX (gearbox module)

IF you can get it over to me (PE16) during the weekend, I can have a look. I don't charge and you'll get a decent cup of coffee too!

Regards
Richard

 

Thanks Richard had a christening do and work this weekend so spare time was non existent. However on the way up to the christening today my engine warning light came on and my voyager wouldn't change gear! So I limped to the christening in what felt like first . After the do light was still on but it's changing gear again??

 

Just done the key dance and got the following error codes.
po65.1
po530

 

That is the code for the B sensor reference voltage and it gives a reference 5V to among other things the A/C pressure sensor which is the other code. I'll look through the diagrams for you tomorrow and give you a bit more info.

Regards
Richard

 

One would assume you did the battery -ve disconnect for a few minutes to hard reset the micros right at the beginning?

Leedsman.

 

The ECU has two reference voltages for various sensor. The B reference is used for the A/C pressure and the boost/ air temp.

options for the failure are:
wiring fault dragging the 5V down
sensor dragging the 5V down
ECU not sending out 5V
or nothing actually wrong with it, but the ECU thinks it's faulty (have seen that with the A reference voltage)

somewhere i did have a schematic which showed which sensor used the A reference and which used the B - but I'll be buggered if i can find it!

Best way to proceed is to measure the B reference voltage at the ECU, if it's below 5V then disconnect the wire and measure again. If then it's still below 5V then it's the ECU and if it's back up then disconnect the sensors one at a time and then see if the voltage returns to 5V.

Pinouts can be found at the end of this document
http://oskin.ru/pub/chrysler-dodge/m...Powertrain.pdf

circuit diagram is 703027 and can be found here
http://1drv.ms/1c7pXkU

Regards
Richard