O2 Sensor
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
O2 Sensor
Hi, I was having a check engine light and the code read "5 blinks" which is an O2 Sensor. I replaced the O2 Sensor with Bosch 13156 and the still keeps on coming back. Any ideas what would cause this?
1991 190e 2.3.
Thanks in advance!
1991 190e 2.3.
Thanks in advance!
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
The diagnostic messaging in these cars is not that precise. Also, something could be wrong with the wiring to the ECU I suppose.
You need to measure the O2 output with a voltmeter to know for sure as the car is running.
Sometimes there are other things that are wrong with the car that will throw the EHA current out of range and you may get an O2 sensor fault.
But I would start with measuring the O2 sensor output and see if that is around 0.5 volts and sweeping between 0.1 to 1 Volts or so periodically (1-2 seconds)
You need to measure the O2 output with a voltmeter to know for sure as the car is running.
Sometimes there are other things that are wrong with the car that will throw the EHA current out of range and you may get an O2 sensor fault.
But I would start with measuring the O2 sensor output and see if that is around 0.5 volts and sweeping between 0.1 to 1 Volts or so periodically (1-2 seconds)
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
The diagnostic messaging in these cars is not that precise. Also, something could be wrong with the wiring to the ECU I suppose.
You need to measure the O2 output with a voltmeter to know for sure as the car is running.
Sometimes there are other things that are wrong with the car that will throw the EHA current out of range and you may get an O2 sensor fault.
But I would start with measuring the O2 sensor output and see if that is around 0.5 volts and sweeping between 0.1 to 1 Volts or so periodically (1-2 seconds)
You need to measure the O2 output with a voltmeter to know for sure as the car is running.
Sometimes there are other things that are wrong with the car that will throw the EHA current out of range and you may get an O2 sensor fault.
But I would start with measuring the O2 sensor output and see if that is around 0.5 volts and sweeping between 0.1 to 1 Volts or so periodically (1-2 seconds)
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
I have not measured my O2 sensor but since Friday, I drove it for 320 miles and no CEL so far. I still would like to check the voltage this week.
I do get some occasional hiccups on idle. It seems like it is cutting off for a quick second but never stalls. Sometimes it will happen once but sometimes frequent. It feels like the ignition is cutting off or maybe fuel. There is no pattern so I am trying to figure this one out too. I replaced all the breather hoses from the crank case to the air filter housing to the ICV to the intake. I replaced spark plugs, caps and rotors. I did not replace the wires as they still look new. I used NGKs thought for spark plugs so I am not sure if that matters.
I do get some occasional hiccups on idle. It seems like it is cutting off for a quick second but never stalls. Sometimes it will happen once but sometimes frequent. It feels like the ignition is cutting off or maybe fuel. There is no pattern so I am trying to figure this one out too. I replaced all the breather hoses from the crank case to the air filter housing to the ICV to the intake. I replaced spark plugs, caps and rotors. I did not replace the wires as they still look new. I used NGKs thought for spark plugs so I am not sure if that matters.
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
There will be a date code stamped on the side of your OVP. Tell me when it was born. Hopefully it is not the original and has been changed. They are not a wear item but most start failing after 10-15 years of usage, or 100K miles.
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
Thanks.....
MBWorld Fanatic!
Joined: Feb 2020
Posts: 1,995
Likes: 394
1991 190E 2.3
I agree with Dolucassi that this might not have been an O2 sensor issue since you're still having issues. It's best to try as best you can to determine which part is at fault so you're not just throwing parts at the problem and hoping that you've solved the issue. That can get very expensive, very quickly. It would be best to stick with an OEM OVP if you find that to be the culprit. Given the age of your OVP, it's likely it's the culprit. You can check its availability at the MB Classic Center's parts catalog that's now online. You might also want to check your fuel filter and fuel lines to make sure that there's no clogging there. I would also suggest checking your distributor cap to make sure that there's no moisture there. Check all of your electrical connections to make sure that no dirt has gotten into them because dirt in electrical connections can cause all kinds of trouble. Also check the condition of your wiring as any frayed wires could also cause trouble.
Trending Topics
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Indeed the Original Siemens or KAE OVP's are going extinct I'm afraid. Either one would work but do not buy a used one. If the dealer sells them go with that. Classic center would be another choice.
My original OVP went bad decades ago around 100K miles around year 2000. Threw a check engine light and the dealer replaced it back then. On my 3rd at 205Kmiles. 2nd one was giving me intermittent stalls unexpectedly, randomly as the OVP was cutting out and back in.
If your OVP is so old it is best to replace it and keep the old one for an emergency. Then we can go back to the diagnostics knowing the OVP is OK.
My original OVP went bad decades ago around 100K miles around year 2000. Threw a check engine light and the dealer replaced it back then. On my 3rd at 205Kmiles. 2nd one was giving me intermittent stalls unexpectedly, randomly as the OVP was cutting out and back in.
If your OVP is so old it is best to replace it and keep the old one for an emergency. Then we can go back to the diagnostics knowing the OVP is OK.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
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
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
Indeed the Original Siemens or KAE OVP's are going extinct I'm afraid. Either one would work but do not buy a used one. If the dealer sells them go with that. Classic center would be another choice.
My original OVP went bad decades ago around 100K miles around year 2000. Threw a check engine light and the dealer replaced it back then. On my 3rd at 205Kmiles. 2nd one was giving me intermittent stalls unexpectedly, randomly as the OVP was cutting out and back in.
If your OVP is so old it is best to replace it and keep the old one for an emergency. Then we can go back to the diagnostics knowing the OVP is OK.
My original OVP went bad decades ago around 100K miles around year 2000. Threw a check engine light and the dealer replaced it back then. On my 3rd at 205Kmiles. 2nd one was giving me intermittent stalls unexpectedly, randomly as the OVP was cutting out and back in.
If your OVP is so old it is best to replace it and keep the old one for an emergency. Then we can go back to the diagnostics knowing the OVP is OK.
MBWorld Fanatic!
Joined: Feb 2020
Posts: 1,995
Likes: 394
1991 190E 2.3
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
Replaced the OVP last Monday. Unfortunately, the problem did not go away. O2 Sensor code came back and the no start issue came back. When it was not starting, I found that the fuel pump was not working. I took out the fuel pump relay and jumped it... at this point, the pump worked. I let the relay our for a while and installed it back. It started right up again... let it idle and then the O2 came back again. I reset it and the car won't start again. Fuel pump out again... took it out, jumped it, and it worked... put back the relay, reset the code and the car started again. I will be replacing the KAE fuel pump relay that is on the car right now and see if that will cure all the issues I am having. Will let update the post when I get and install the fuel pump relay.
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Replaced the OVP last Monday. Unfortunately, the problem did not go away. O2 Sensor code came back and the no start issue came back. When it was not starting, I found that the fuel pump was not working. I took out the fuel pump relay and jumped it... at this point, the pump worked. I let the relay our for a while and installed it back. It started right up again... let it idle and then the O2 came back again. I reset it and the car won't start again. Fuel pump out again... took it out, jumped it, and it worked... put back the relay, reset the code and the car started again. I will be replacing the KAE fuel pump relay that is on the car right now and see if that will cure all the issues I am having. Will let update the post when I get and install the fuel pump relay.
If you have a 20A capable current meter or a meter with a current probe you can measure the current thru each pump. They are supposed to draw between 5A -10A (closer to 10A believe) each
Fuel Pump Relay's are pretty pricey as I recall, if you can find a spare used one just to try it is worth it. I have a spare just for a case like yours, though mine is still the original in there at 205Kmiles.
MBWorld Fanatic!
Joined: Feb 2020
Posts: 1,995
Likes: 394
1991 190E 2.3
I agree with Dolucassi's testing recommendations in an effort to try to determine the actual culprit part. Throwing parts at a problem can get very pricey very fast. It does sound like it might be either possibility so I think checking to make sure that the fuel pump isn't drawing too much current might be a good next step because if the fuel pump isn't drawing too much current then that makes it more likely that the fuel pump relay is the culprit. Keep us posted on your findings.
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
So I replaced the fuel pump relay and did the fuel pump and fuel filter as well as week later. Those are 32 years old and I believe its time to replace them even though they are still functional. I just don't want to have issues with the fuel pump later on. No more no start and no more CEL.
I do have one question -- I wanted to check the duty cycle on my car. Since this is a CA car, do I need to press the button for 2 to 4 seconds on the X92 port before I can measure the duty cycle on X11 port (#2 and #3)? I am having trouble getting readings on those pins. Can you share any info on how to do it on CA cars?
Thanks,
Peter
I do have one question -- I wanted to check the duty cycle on my car. Since this is a CA car, do I need to press the button for 2 to 4 seconds on the X92 port before I can measure the duty cycle on X11 port (#2 and #3)? I am having trouble getting readings on those pins. Can you share any info on how to do it on CA cars?
Thanks,
Peter
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
I figured this out. You need to press the button for 2 to 4 seconds… after 1 blink of the LED, assuming there is no fault codes, you need to press it again for 2 to 4 seconds. After this I was able to read the duty cycle from the x11 port. I was at 80% so I adjusted it to the correct % — 50%.
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Great! Yes, sometimes it takes 2 tries for me too. Since it was off and you re-adjusted it, I assume you also checked the duty cycle at 2500rpm. and made sure it does not move more than 10% on average compare to idle duty cycle (positive or negative).
- Cheers!
- Cheers!
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
Yup, did that too...
Junior Member
Joined: Nov 2009
Posts: 25
Likes: 4
1990 190E 3.0
I figured this out. You need to press the button for 2 to 4 seconds… after 1 blink of the LED, assuming there is no fault codes, you need to press it again for 2 to 4 seconds. After this I was able to read the duty cycle from the x11 port. I was at 80% so I adjusted it to the correct % — 50%.
Thread Starter
Member
Joined: Aug 2013
Posts: 153
Likes: 2
From: Bay Area CA
1991 190e 2.3
