check engine light
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 32
Likes: 0
300E
check engine light
hello evryone. i acquired a 1989 300e with 200k on the odo. it actually runs well however, the engine light recently came on and i need to get it smogged. i have no service history for the car so not sure where to start. maybe o2 sensor or ? any advice would help. trying to get it straightened out so the kids have a safe car to drive around in. i had heard that you could possibly use a o2 sensor from a mustang? what year? v6 or v8? is it direct fit or modified? thanks
Last edited by smoothaseggs; Aug 8, 2010 at 09:26 PM. Reason: sp
Member
Joined: Jul 2006
Posts: 100
Likes: 0
From: Phoenix, AZ
400E
You have an 89 with a check engine light? It actually says "check engine"? If so it must be a CA version, in which case you should be able to read the fault codes on the diagnostic connector in the engine compartment. A Bosch universal O2 sensor for your car is only $57 at AutohausAZ - hardly worth messing with a Mustang sensor. The OE plug version is only $82.
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 32
Likes: 0
300E
it is a ca car. i thought of the mustang o2 sensor cause both the bosch universal and the mustang bosch needs to be spliced. what is the procedure for reading the fault codes. i'm guessing it is a series of beeps.
MBWorld Fanatic!
Joined: Apr 2007
Posts: 6,171
Likes: 16
300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
You have a blink
box up by the battery.
You read the blinks and since your model only had about 5 inputs for cel at those miles it most likely is the 02 sensor.
harness to unplug it is under the pass floor carpet.
Enjoy
You read the blinks and since your model only had about 5 inputs for cel at those miles it most likely is the 02 sensor.
harness to unplug it is under the pass floor carpet.
Enjoy
Member
Joined: Jul 2006
Posts: 100
Likes: 0
From: Phoenix, AZ
400E
Flashes rather than beeps. Can you take a picture of the area around your battery, or tell us what diagnostic connector you have?
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 32
Likes: 0
300E
i looked near the battery today and i found the little black box. i pulled the lid to see the numbers and the sockets near the numbers. with the car running the red led is on constantly. i turned the car off then moved the key to the on position. i then pushed the button for approx 1-3 seconds and the the light flashed 4 times then i think it flashed once then glowed steadily. i tried pushing again and no more flashing. did i have the correct procedure. thanks for the help
Member
Joined: Jul 2006
Posts: 100
Likes: 0
From: Phoenix, AZ
400E
With the ignition on, warning lights on, car not running, hold the button down for 3 seconds, LED should go on, release button, LED should go off, count the number of flashes that follows, repeat until the same code comes up again. To delete codes, within 20 seconds of reading the code, hold button down for 8 seconds, again LED should go on, release button, LED should go off, turn ignition off for several seconds between each code deletion.
Code 4 is air flow sensor position indicator. Code 5 is oxygen sensor.
Code 4 is air flow sensor position indicator. Code 5 is oxygen sensor.
Trending Topics
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Member
Joined: Jul 2006
Posts: 100
Likes: 0
From: Phoenix, AZ
400E
That's probably referring to the potentiometer that attaches on the side of the air flow meter. It was never available as a separate part from Mercedes but was available through Bosch for about $40. But then they discontinued it and you had the buy the whole air flow meter for about a thousand. But I noticed it recently came back - as a $200 part. Europartsdirect.com has them. But it's too soon to start buying parts - you need to delete the code, drive the car, read the codes a few times - in other words make it come back, and make sure they aren't any more codes.
MBWorld Fanatic!
Joined: Apr 2007
Posts: 6,171
Likes: 16
300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
I thought
you said it blinked 5 times?
Check again like above so you can order the right part.
O2 sensor is more common and far cheaper.
Check again like above so you can order the right part.
O2 sensor is more common and far cheaper.
Thread Starter
Junior Member
Joined: Aug 2010
Posts: 32
Likes: 0
300E
checked the flashes again and it definiteley is/was 4 flashes. i went ahead an cleared it and there were no other codes. i have only driven it a little bit but has not popped back up. gonna drive it more to see if anything comes up. any way to clean the air flow pot or whatever is setting off the code 4
Member
Joined: Jul 2006
Posts: 100
Likes: 0
From: Phoenix, AZ
400E
Given the price of the part that's probably what I would do, take the whole thing off and clean it with throttle body cleaner and electrical contact cleaner, not that it's likely to work but it might and it doesn't cost anything. You can always buy the part later.
