Technical Vehicle Speed for Ducato X244 2.8 JTD 2006

[sjdtuk]

Hi. I have the above Motorhome. The speedo works just fine. The issue is the vehicle speed from the OBD
show 143 mph as soon as I start moving and then a little later the engine warning light turns on. Probably as
the throttle position and speed confuse the ECU.


This sounds like a vehicle speed sensor to me? Does anyone know where it is(and its wiring) and how to source a replacement, if necessary.

Thanks

Stephen

 

[Communicator]

I am not confirming or rejecting your diagnosis.

Vehicle speed sensor is at rear of gearbox. See attached photo. Plenty options for sensors available on Ebay.

 

[sjdtuk]

I am not confirming or rejecting your diagnosis.

Vehicle speed sensor is at rear of gearbox. See attached photo. Plenty options for sensors available on Ebay.

Thanks for the. The speedo is still working correctly. Its just the vehicle speed seen by the ECU that is wrong. Is this possible?
Thanks

 

[Communicator]

Thanks for the. The speedo is still working correctly. Its just the vehicle speed seen by the ECU that is wrong. Is this possible?
Thanks

The speed signal pulse train is processed in the instrument panel, and used to drive a stepping motor for the analogue dial. It may be that your diagnostics are not applying the correct scaling factor. Never tried to read this from OBD2 port, so cannot be sure. What are you using?

 

[sjdtuk]

Just a bluetooth one and my phone. Nothing special. Rpm is correct though. What is weird is that the engine management light comes on as soon as you start driving. The code is complaining about inconsistency of throttle position. Engine seems to work fine though. When you stop the engine for 5 minutes and start it again - it goes off and will run in neutral for a long as you like.

 

[Communicator]

Just a bluetooth one and my phone. Nothing special. Rpm is correct though. What is weird is that the engine management light comes on as soon as you start driving. The code is complaining about inconsistency of throttle position. Engine seems to work fine though. When you stop the engine for 5 minutes and start it again - it goes off and will run in neutral for a long as you like.

Suggetions
1. If you have cruise control, is the brake pedal switch sticking? Or are you catching brake pedal and accelerator at same time?
2. Possible problem with accelerator potentiometers or wiring.

 

[sjdtuk]

Suggetions
1. If you have cruise control, is the brake pedal switch sticking? Or are you catching brake pedal and accelerator at same time?
2. Possible problem with accelerator potentiometers or wiring.

Def not 1. Could be 2.