Technical throttle body p0638 on 3.0JTD

[mejsny]

Hi,
I'm a bit desperate with fault code p0638 on 3.0JTD Ducato 2009

Bought a used throttle body but it wouldn't work at all (the flap doesn't move). So I ordered a new one, but still the same problem.

Would anyone be able to measure their voltage on the connector? Mine has 3.5V on first wire and just over 11V on second one (the older version of throttle body)

Is that wrong or do I just have bad luck and bought two faulty items?

Any help appreciated.

 

[taffybloke]

Check out this post.

https://www.fiatforum.com/ducato/307773-p0638-throttle-actuator-control-range.html

Mike

 

[andydiver]

This is caused very often by corrosion in the connector, unfortunately in the block which stays with the loom, so replacing the valve actuator won't fix it unless you repair or replace the connector block on the loom. Also, on mine and many others on here, there is potential for bad connection in the fuse box under the headlight... Look for the big black box near the air filter next to the light, deep in there there are multiple connections which might need cleaning. Some have found chaffing wires under the light but you have to remove it to see. Most likely the connection direct on the actuator. Multiecuscan has a test function for this actuator which works on ignition only, very handy.