Engine ecu location please

Pipes · Post by **Pipes** » 03 Mar 2010, 08:38

Hi,
After changing both O2 sensors I still have the pesky light on my dash.Im going to try changing the ecu but i dont know where it is.
Is it correct that i have to have it programmed at Volvo?
Many thanks Peter

Post by **polskamafia mjl** » 03 Mar 2010, 08:43

Replacing the ECU is very rarely done if ever and usually when it is done it is for purposes of upgrading it to handle more boost, etc. What code(s) did you get? Did you try resetting the code(s)? A vacuum leak could aslo cause codes that point to O2 sensor failure.

Post by **jblackburn** » 03 Mar 2010, 08:56

Ahh! Not the ECU!

A vacuum leak could also cause codes that point to O2 sensor failure.

This is actually the most common cause of it throwing O2 codes. Poke around and check for cracked or loose lines or elbows. A can of carb cleaner will greatly assist you in this task, spray around with the engine running and listen for changes in the idle. There is one behind the alternator/PS pump, and another under the battery tray that are common suspects, as well as the ones around the throttle body/intake manifold.