[cef2lion]

I have a 2004 Deville base (110K). It had an over heating issue when I got it for next to nothing. I thought at first it passed the block test but I re-tested right after an over heat issue. Color changed slightly. My thoughts are to repair it since its in such good shape.I have been running it on short trips to town and back on colder days. 3 Miles at best.

This past weekend I pulled in the driveway and shut it off. I heard something running/buzzing under the hood or a sound like that. At first I thought it was the cooling fans but they didn't appear to be turning. I let it sit with hood up and walked in the house. When I came back out I could smell something electrical. Then I noticed a bit of smoke, not much, coming up around the air box. The noise was gone. I disconnected the battery. I thought at first it was coming from the ECU. But how could the ECU make the noise I heard? I took the air box apart. The ECU looked OK and wasn't hot. No melted wires. I left the air box out and set the ECU on a small board. I had other things to do.

This morning I connected the battery and it started up and I drove it around the yard. No codes. I didn't let it heat up. I thought if the ECU fried it wouldn't start. I'm not sure where the issue came from now. The ABS is below the air box and there is the cooling fan on the drivers side. Unless it was something else. I will start it and turn AC high to make sure both cooling fans running ok. And also check battery voltage running.

 

[Submariner409]

Trouble codes ?

Electrical smell, humming, smoke - airbox area - ABS/EBCM motor, AIR blower.

 

[cef2lion]

Thank you!

It did sound like the ABS running after shutoff. Noise was right under air box. By time I got the battery disconnected the smoke was gone so I couldn't locate the source. Just the area. Could a stuck ABS relay cause this?

By AIR blower. What are you referring to?

Inside the drivers front fender I saw so tubing coming up from the bottom of radiator area. What could that be? Never noticed it before.

 

[Submariner409]

AIR is a system that sends fresh air to the exhaust manifolds on cold start to quickly light off the cat. It uses a blower, piping, check valves, and solenoid-controlled vacuum. The blower sounds much like a vacuum cleaner when the splash shield/cover rots off. It's down in the fenderwell inside/in front of the LF wheel. ......It's the modern day version of the old "smog pump".

Use the correct section of the sticky thread at the top of this forum page - "How to pull codes" - to retrieve any diagnostic trouble codes (DTC) from your car's built-in code scanner/memory.Use the section by JimD. There's also a link in there to definitions of all our trouble codes. Define any found codes and post it all here.

Here are the DIC control buttons you use to operate the code scanner.

 

[cef2lion]

Thanks again. I didn't know about the AIR blower. Interesting. I have a cheat sheet in the car to pull codes. I also have a ODBCII program called Autoenginuity that I use with my laptop. I don't have a check engine light but will look for code next. Is the AIR system sensor driven?

 

[Submariner409]

AIR is triggered by the PCM and operation depends on time since last start, ambient temperature, coolant temperature, O2 sensor inputs, others.

The operating relay is gray, with a blue electrical connector, clipped to the right strut tower. The system is an emissions control, so a (monitored) fault usually sets the SES logo.

 

[cef2lion]

I finally got a chance to pull codes. P0410 - Secondary AIR Injection System. Looks like the noise was the AIR pump still running at shutdown. I tested 30-87 on relay off car with ohm meter. It was open.

 

[cef2lion]

Going to see if I can test pump see if it burnt up. Could the relay 30-87 stuck closed on shutdown? Going to check for power at 30 relay connector at key off. See if it has power all time. If I jump 30-87 at connector will this test AIR pump so I can hear it?

 

[cef2lion]

I had 12V at the 30 relay wire at the relay with key off. I jumped 30 to 87 at the connector. The AIR pump didn't run. Assume AIR pump has burnt up and needs replaced. Going to replace he relay as well.