I'd like to bounce this off youse guys.

Problem: 2000 S40 Poor Drivability No OBD codes set.

Fix: Replaced Front turn signal bulb.


Stay with me.


The turn signal indicated a burned out bulb by blinking rapidly. Checked bulb and found a crispy burnt turn signal connector and perfect filament. The snap in bulb plastic bit was charred. Evidently arcing was occurring.

Replaced bulb, cleaned socket of heavy oxidation, replaced turn signal assembly.

Now the car is running smoother, less hesitation.

Sooooo....

Was the arcing causing a noise signal on the electrical lines thus screwing up the computer ? Is there filtering on the computer connector that anyone knows of ?

Lesson learned : Keep any and all electrical connector/connections clean and all grounds tight.

An engine is an extremely (electrically) noisy environment. Anyway, if noise gets into the computer it will store an error code. However, that noise could have coupled into a nearby sensor resulting in a measurement error at the sensor (rather than in the computer) with resulting drivability issues. Most sensor measurement errors will not cause an error code, because e.g. how would the computer know the temperature sensor is reading 10 degrees high?

So noise could have caused problems, but rather I would think you also have poor contact on a sensor connector. Sounds like perhaps water got into your connectors, which would cause them to corrode.

Niel

I really believe the daytime running lights made it very warm in the signal housing, causing the plastic bit to warp loosing contact. Actually there was a very good seal at the connector. VERY clean inside the connector when I unplugged it.

I'll check around the area though for other connectors, sensors which might be affected.

Thanks

Miker