Idle fluctuating

[Mark1971]

When sitting at idle my vans revs go up and down constantly between about 900 to 1000 , when driving it runs ok until I come to rest again then keeps going up and down.Have been having this problem for few days ,then it went away, but has come back isn’t showing any fault codes ,any help appreciated

 

[Kind of Blue]

When sitting at idle my vans revs go up and down constantly between about 900 to 1000 , when driving it runs ok until I come to rest again then keeps going up and down.Have been having this problem for few days ,then it went away, but has come back isn’t showing any fault codes ,any help appreciated

Hello Mark1971 a very good year. Do you think that it is trying to regenerate?

 

[Mark1971]

Hello Mark1971 a very good year. Do you think that it is trying to regenerate?

I’ve had a lot wrk done on van and the dpf has been deleted as had dreaded CFCA engine my van is 2013 sportline

 

[Mark1971]

Still not sorted this out ,had it in couple local garages,at a couple of hundred £ a shot. So have been doing few tests myself and while doing that fault code
P012300 - Throttle/Pedal Position


Sensor/Switch "A": Circuit High came on , tested voltage on connector to throttle body and the sensor wires are fluctuating constantly 3 to 12 v with key on engine off , the other wires 5v , 5v and ground are fine, could this be the issue causing idle problems, any advice, help appreciated, Mark

 

[manfrotto]

Still not sorted this out ,had it in couple local garages,at a couple of hundred £ a shot. So have been doing few tests myself and while doing that fault code
P012300 - Throttle/Pedal Position


Sensor/Switch "A": Circuit High came on , tested voltage on connector to throttle body and the sensor wires are fluctuating constantly 3 to 12 v with key on engine off , the other wires 5v , 5v and ground are fine, could this be the issue causing idle problems, any advice, help appreciated, Mark

Spounds like it - possibly a bad connection at the throttle/pedal.

 

[Mark1971]

Spounds like it - possibly a bad connection at the throttle/pedal.

Thanks for reply , I have tested voltage at pedal seems ok from what I’ve researched but still not ruled it out was going to buy one of eBay the other day just to try it , but definitely thinking my problem is the wiring somewhere, thinking might try tracking wire back to ecu to see what voltage it’s giving out , or trying auto electrician if can’t find what’s wrong.

 

[mmi]

So have been doing few tests myself and while doing that fault code
P012300 - Throttle/Pedal Position


Sensor/Switch "A": Circuit High came on

What exctly were the tests? Can you reproduce the P0123 00?

I have tested voltage at pedal seems ok from what I’ve researched but still not ruled it out

P0123 00 is a fault of throttle valve in engine air intake path - nothing to do with the accelerator pedal. I think the diagnostic tool translation is misleading.

but definitely thinking my problem is the wiring somewhere, thinking might try tracking wire back to ecu to see what voltage it’s giving out , or trying auto electrician if can’t find what’s wrong.

A proper diagnostic tool could be a time&money saver? E.g. to monitor throttle commanded and actual positions.

 

[Mark1971]

What exctly were the tests? Can you reproduce the P0123 00?


P0123 00 is a fault of throttle valve in engine air intake path - nothing to do with the accelerator pedal. I think the diagnostic tool translation is misleading.


A proper diagnostic tool could be a time&money saver? E.g. to monitor throttle commanded and actual positions.

What exctly were the tests? Can you reproduce the P0123 00?


P0123 00 is a fault of throttle valve in engine air intake path - nothing to do with the accelerator pedal. I think the diagnostic tool translation is misleading.


A proper diagnostic tool could be a time&money saver? E.g. to monitor throttle commanded and actual positions.

 

[Mark1971]

Again thanks for reply’s , thinking of just ordering throttle body to give it a try

 

[Mark1971]

What exctly were the tests? Can you reproduce the P0123 00?


P0123 00 is a fault of throttle valve in engine air intake path - nothing to do with the accelerator pedal. I think the diagnostic tool translation is misleading.


A proper diagnostic tool could be a time&money saver? E.g. to monitor throttle commanded and actual positions.

This is throttle positions at idle

 

[mmi]

This is throttle positions at idle

They look normal.

Have you monitored fuel pressure & regulator status, mass air flow, injection deviations, charge pressure, etc. - do they follow the RPM?

 

[Mark1971]

They look normal.

Have you monitored fuel pressure & regulator status, mass air flow, injection deviations, charge pressure, etc. - do they follow the RPM?

Don’t really know all that, but did see on Carista obd that fuel rail pressure jumps up and down at idle as does the rpms