03 2.2DTi - P0638, P0234 codes advice - PeterA
Once my vauxhall signum 2.2DTi, diesel, automatic, sept 2003 has warmed up, anything more than very gentle accelaration causes "spanner" to appear & car to go into limp home mode. Switching off ignition & restarting clears spanner & limp home until it repeats.

Fault Codes:
P0638 Throttle Actuator Control Range/Performance (Bank 1)
&
P0234Turbo/Super Charger Overboost condition
get stored as pending in ECU.

What is the most likely cause or what should I check next?

Edited by Pugugly on 21/04/2009 at 18:04

2003 2.2DTi - P0638, P0234 codes advice - LukeH
Hi
I had the same problem and it turned out to be a split in the vaccum hose, mine was located at the front of the engine bay on the right hand side. I think there are two or three pipes and the tech had to replace a small piece of rubber tubing about 1.5 inches long. This did the trick for me.