[petemon]

Hi all.

My radiator fans don't come on when the car heats up, haven't since I've had the car.

If I jumper the diagnostic port on the ECU they run.

I hooked up Espritmon and watched as the (ECU) coolant temp sensor went past 100 C, no fans. For some reason, the "code 26" buttons in Espritmon are disabled so I couldn't try activating them that way. I do have an intermittent code 26 QDMB.

My AC has a leak but if I bypass the low-pressure switch and turn the AC on, the compressor runs and the fans kick on. I also get a little puddle of AC oil near the LEFT front wheel, but that's another topic.

I'm leaning toward a problem with the ECU since the fans activate by every other expected means and the coolant sensor seems to be ok.

I do have an unknown non-stock MemCal installed by the PO, seems like I would see lots of other problems if it was corrupted/faulty tho. The only other issue is a rough idle, worse when cold but still not very smooth when warm.

Any thoughts would be greatly appreciated.

 

[sailorbob]

Have you checked the radiator fan control relay?

 

[petemon]

Hi Bob.

I figured it was OK since they worked with the diagnostic jumper. Is there more than one way to activate them? I know there is one relay on the rear panel and one on the front one but it looks like they are in series.

In any case, I noticed on the way home that they are working now.

I'll keep an eye on them and report back if I see they quit again. Nothing worse than an intermittent problem. :shrug:

 

[sailorbob]

It is the ecu controlled one in the rear you need to check as the front one seems to be working (as indicated by the fans coming on when you bypassed the A/C low pressure switch).