Hi!

I have a 2006 S40 non-turbo that has about 110k miles. Drives great until the weather warms up and it rains or gets muggy out. Then the car begins to stall, shout “reduced engine performance” and leaves me sitting in traffic with angry motorists honking and gesturing. I either eventually get it started by cranking on it and keeping the gas pedal down - or else end up having someone help me limp over to a parking lot. Once it dries out or cools slightly (below like mid 80s outside) - no more issue - no more “throttle body” or “throttle valve” codes.
I have cleaned the throttle body and replaced the throttle body, but still - the temperature and humidity levels outside can dictate a bad day. I just cleaned it again and cleared the codes - but I can’t keep sitting in traffic with a car that won’t move. Any advice or thoughts on what would cause this message that just registers as the throttle body? Do you think something else might be going on in the electrical or computer systems?
thanks for any suggestions!!

 

It would be (very) helpful if you could post the actual OBD codes the car is throwing.

 

You’re right that probably would be helpful:

ECM-91AC - Throttle Valve
ECM-9918 - Throttle Valve

The last time also indicated throttle body, but this time just the two.

thanks!

 

Have you inspected the wiring going to the TB for frays or deteriorating insulation?

 

Could be a thermally intermittent ECM, bad cabling, or I suppose the throttle body (hard to imagine two with the same problem, but it CAN happen).

This is where it's nice to have deeper diagnostics (a laptop loaded with VIDA software is ideal). Barring that, you could possibly use something like the Torque (or $5? Torque Pro) app and a Bluetooth "dongle", which will allow you to read things like throttle and accelerator position, maybe giving you some clues as to the issues.