Hi All,

I tried searching the archives and didn't find the answer.

My '98 S70 GLT had the CEL come on. I used the Equus 3030 reader and it showed no code thrown.

So, I reset the light and now the I/M monitors for the heated O2 sensors, secondary air system, cat and evap systems (IIRC) are cycling through self-diagnostics.

The guy at the auto parts store said to clean the MAF sensor so I picked up a can of cleaner.

Ghost in the machine?

Thanks,
Bryan

I would have tried the auto parts store code reader before unplugging the battery. There is something wrong with your code reader: Any code that sets a CEL is readable via Pnnnn. No code reader should reset the drive cycle.

Klaus
--
Praying for Cynthia Amendt, heaven bound

Hi Klaus,

It's weird I know.

I didn't unplug the battery. Here is the procedure I followed:

1. CEL on
2. Connected reader to OBD II port
3. Turned ignition on but did not fire engine
4. Reader interfaced with car computer
5. NO DTCs but caution light came ON for reader and named I/M monitors were flashing
6. Pressed Erase/Reset button
7. CEL off

So, you're right. The reader didn't trigger the I/M monitors.

Why would they be going through a diagnostic-cycle and did this set the CEL?

Thanks again for your help,
Bryan

I/M monitors cannot set the CEL, only an error code for the engine, tranny, or emissions can set the CEL. The only thing that I can think of to initiate a new drive cycle is a dead battery or disconnected battery. The drive cycle can take a long time to reset.

Klaus
--
Praying for Cynthia Amendt, heaven bound

Hi Klaus,

I did add a hard-wired battery maintainer a while back.

Maybe when I was loosening and tightening the cable bolts the connection was interrupted. But, I didn't have the radio go off or lose the info on the clock.

Anyway, I cleaned the MAF and will wait to see what happens after the monitors complete their drive cycle.

Thanks much.

Bryan