Code 33 and running like CRAP - 1985
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 164
From: Nashville TN
2017 C4 of Year Finalist
Code 33 and running like CRAP - 1985
2 days ago my alternator burned out while I was away from home. Drove the car home on battery, had to stop and have it charged up a few times on the way. The voltage hit a low of 5.8 volts or so before stalling once on me.
Fast forward to today-new alternator installed, takes off and runs beautifully...for a half mile. Then she starts running like absolute crap, won't rev at all, can't really get over 15 mph. I stop, open the hood, look around, nothing seems to have changed under there. Check codes, I'm getting code 33. I look up and it's the MAF sensor. I find it odd that it would go out right after I was dealing with low voltage/bad alternator issue, I'm suspecting something happened there.
I start to drive back home, halfway there she seems to forget there was a problem and starts running perfectly again. It's like something is intermittent because she kept cutting in and out of running like garbage. I don't actually think the sensor is bad, because of how it kept cutting in and out-it screams electrical issue to me. Anyone have any ideas?
Fast forward to today-new alternator installed, takes off and runs beautifully...for a half mile. Then she starts running like absolute crap, won't rev at all, can't really get over 15 mph. I stop, open the hood, look around, nothing seems to have changed under there. Check codes, I'm getting code 33. I look up and it's the MAF sensor. I find it odd that it would go out right after I was dealing with low voltage/bad alternator issue, I'm suspecting something happened there.
I start to drive back home, halfway there she seems to forget there was a problem and starts running perfectly again. It's like something is intermittent because she kept cutting in and out of running like garbage. I don't actually think the sensor is bad, because of how it kept cutting in and out-it screams electrical issue to me. Anyone have any ideas?
Instructor
Joined: Dec 2016
Posts: 241
Likes: 77
From: Arlington VA
2 days ago my alternator burned out while I was away from home. Drove the car home on battery, had to stop and have it charged up a few times on the way. The voltage hit a low of 5.8 volts or so before stalling once on me.
Fast forward to today-new alternator installed, takes off and runs beautifully...for a half mile. Then she starts running like absolute crap, won't rev at all, can't really get over 15 mph. I stop, open the hood, look around, nothing seems to have changed under there. Check codes, I'm getting code 33. I look up and it's the MAF sensor. I find it odd that it would go out right after I was dealing with low voltage/bad alternator issue, I'm suspecting something happened there.
I start to drive back home, halfway there she seems to forget there was a problem and starts running perfectly again. It's like something is intermittent because she kept cutting in and out of running like garbage. I don't actually think the sensor is bad, because of how it kept cutting in and out-it screams electrical issue to me. Anyone have any ideas?
Fast forward to today-new alternator installed, takes off and runs beautifully...for a half mile. Then she starts running like absolute crap, won't rev at all, can't really get over 15 mph. I stop, open the hood, look around, nothing seems to have changed under there. Check codes, I'm getting code 33. I look up and it's the MAF sensor. I find it odd that it would go out right after I was dealing with low voltage/bad alternator issue, I'm suspecting something happened there.
I start to drive back home, halfway there she seems to forget there was a problem and starts running perfectly again. It's like something is intermittent because she kept cutting in and out of running like garbage. I don't actually think the sensor is bad, because of how it kept cutting in and out-it screams electrical issue to me. Anyone have any ideas?
So far I've redone the MAF connector and looked all over but the darn thing is so intermittent...
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
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From: Nashville TN
2017 C4 of Year Finalist
The fact this happens RIGHT after my alternator issue implies to me that's the cause. I could be wrong of course but it's way to much of a coincidence I think.
Wires look ok for the pigtail. I reset codes and it came back immediately while just idling. Also removed MAF to inspect, looks good to me. Wiring also looks ok.
Can low low voltage damage this stuff? I'm wondering if the ecm is burned up somehow?
Wires look ok for the pigtail. I reset codes and it came back immediately while just idling. Also removed MAF to inspect, looks good to me. Wiring also looks ok.
Can low low voltage damage this stuff? I'm wondering if the ecm is burned up somehow?
Instructor
Joined: Dec 2016
Posts: 241
Likes: 77
From: Arlington VA
Heres the code33 flow chart. It's F body but it's the same for Y. Although low voltage can be a problem with some electrical-mechanical devices, I'd just want to check out the wiring, etc before I'd go to the ECM, relay and so on.Yes it seems odd to be a coincidence but maybe.
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 164
From: Nashville TN
2017 C4 of Year Finalist
can someone provide some plain English troubleshooting for me? I think I've read the FSM correctly but I want to be sure.
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 164
From: Nashville TN
2017 C4 of Year Finalist
New plot twist: Completely disconnected the MAF, cleared all codes, started the car, and code 33 immediately set. I'm thinking it might be the ECM in this case. Why else would code 33 set with the sensor disconnected?
My theory is I managed to F*ck up the computer driving it with low voltage.
My theory is I managed to F*ck up the computer driving it with low voltage.
Last edited by Bfenty; Jun 2, 2017 at 11:41 AM.
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Drifting
Joined: Mar 2013
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From: Venice Cali.
Thread Starter
Drifting
Joined: Mar 2017
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From: Nashville TN
2017 C4 of Year Finalist
More info (can someone out there confirm they have similar on their car?
I connected volt meter to each wire in the MAF connector. first two wires (red and blue, I think) are ~ 0.4 v each. green wire is 5 v. the last two are grounds, no voltage coming through them. Is this normal operation?
I connected volt meter to each wire in the MAF connector. first two wires (red and blue, I think) are ~ 0.4 v each. green wire is 5 v. the last two are grounds, no voltage coming through them. Is this normal operation?
Drifting
Joined: Mar 2013
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From: Venice Cali.
Bf I am terrible with a voltmeter I only know how to check batteries and tpi setting.
I think you should inspect connectors and wires once confirmed looking good and clean, disconnect the battery and start over. That will reset your computer.
Just an idea.
Good Luck
I think you should inspect connectors and wires once confirmed looking good and clean, disconnect the battery and start over. That will reset your computer.
Just an idea.
Good Luck
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Only other thing I can think to check is to check the burnoff module directly as well, it will not be a fun job to get it out but MAFs tend to be trickier to troubleshoot. And check the Gauges 10A fuse if you aren't getting power on the purple wire leading into the MAF. A current spike from a dying alternator could've fried the fuse.
If that is not it, I think the best bet is to get a MAF from another 85 and test it.
If that is not it, I think the best bet is to get a MAF from another 85 and test it.
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 164
From: Nashville TN
2017 C4 of Year Finalist
Only other thing I can think to check is to check the burnoff module directly as well, it will not be a fun job to get it out but MAFs tend to be trickier to troubleshoot. And check the Gauges 10A fuse if you aren't getting power on the purple wire leading into the MAF. A current spike from a dying alternator could've fried the fuse.
If that is not it, I think the best bet is to get a MAF from another 85 and test it.
If that is not it, I think the best bet is to get a MAF from another 85 and test it.
Drifting
Joined: Mar 2013
Posts: 1,952
Likes: 239
From: Venice Cali.