My wife's e320 had a voltage regulator go out (alt was charging at 17V). After replacing the regulator, the car is charging normally. The problem is the check engine light. It is on when the car/key is turned off. I tried search, but didn't see anything about the CEL being on with the key off.

Any suggestions are appreciated.

Thanks,
Todd
95 E320 Wagon 179k

May have fries OVP feed circuit..
Pull ovp and see if it goes out.

Do you have an ABS light on??
Is the led on the diagnostic box working??

Thanks for the quick reply.

No ABS light. It seems normal. I checked the OVP fuse, but I'll check the light with the fuse out tomorrow. The light does of course turn off when I pull the #9 fuse.

If anyone else has other suggestions, please serve them up.

Thanks,
Todd

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The LED lights up when the button is pushed (key on or off). Ign on/off and holding down the button doesn't seem to produce any flashing.

Todd

Try

Key on
press button for 2/3 sec, release .
wait for a few secs..any flash come back?
If YES, after flash comes back , hold button for 8 secs ..turn off key for 10 sec , On for 10 secs. and then start car..
CE go out?

Pulled fuse out of OVP and CEL went off (key is off). Did the reset you described and restarted moter. CEL was out, but came on when I turned off the car. OVP shot?

Todd

Did any flashcode come back with the procedure????

16 flashes.

Todd

Correction 17.

Todd

Please tell me this stuff
My questions are in sequence and have to be answered as posted.

OK
Go back to led/sw and Key ON
press button 2/3 sec
Count flashes that come back
Repeat..you will get more flashes , but a higher number [ codes come back in numerical sequence]
Continue the same process for each code until the original code comes back..then you know all codes have been retrieved.
Then go turn key Off for 10sec , On for 10 sec and start car.. Post that finding

After following this procedure I only got 17 flashes each time (the only code). The CEL went out when the car started, but came back on after the key was turned off.

Todd

Please tell me this stuff
My questions are in sequence and have to be answered as posted.

OK
Go back to led/sw and Key ON
press button 2/3 sec
Count flashes that come back 17 flashes
Repeat..you will get more flashes , but a higher number [ codes come back in numerical sequence] 17 flashes again
Continue the same process for each code until the original code comes back..then you know all codes have been retrieved.
Then go turn key Off for 10sec , On for 10 sec and start car.. Post that finding Check engine light came on when the car was turned off.

Very good.

Ok.. I suspect you have either a short to pin #7 on the OVP or it is hanging up.

You want to pull it and see if the part # is 000-540-52-45..if it is, just change it regardless . That was a bad relay and has been replaced by 000-540-67-45.
Also , with key off and CE lamp On , try tapping the relay w/screwdriver handle a few time and see if those contacts drop out and if the CE turns off

Thanks for your help Aurthur. I'll play around with it tomorrow.

Have a great weekend,
Todd