S5 MOP and/or ECU Failure Diagnosis
01-02-08, 08:55 AM
#51
Junior Member
Join Date: Dec 2007
Location: Georgia
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
I'm not looking for a temporary fix to this problem. I tested my TPS and it checked out just fine. I even went as far as to check my Timing, Secondary injectors, CAM, COILs, and EGI. I'm not a mechanic but I do have some experience in electronics.
Changing out the ECU and the pump is one thing, but I want to ensure that I won't ever have to do that again.
Everything up until this point I could think of check has checked out ok. The only thing left is the ECU and if that is the cause, then replacing it would be easy.
I got some schematics so i'm going to check it out.... thanks.
Changing out the ECU and the pump is one thing, but I want to ensure that I won't ever have to do that again.
Everything up until this point I could think of check has checked out ok. The only thing left is the ECU and if that is the cause, then replacing it would be easy.
I got some schematics so i'm going to check it out.... thanks.
01-02-08, 11:54 PM
#52
yessir
iTrader: (24)
Join Date: May 2005
Location: Sebring FL
Posts: 722
Likes: 0
Received 0 Likes
on
0 Posts
thanks alot
i found this thread, and it has helped alot....
I made a small error wiring, while trying to run my harness a different route, and plugged the TPS connector on the harness into my OMP.
It "safe moded" my ECU, so I bought another ECU and fixed the connections, and tryed it again... and another computer went to the dirt...
I really didnt believe plugging the OMP into your TPS connector would break it to where it would keep frying ECU's..
I always just thought it was an ECU problem...
After 2 computers I know now...
I made a small error wiring, while trying to run my harness a different route, and plugged the TPS connector on the harness into my OMP.
It "safe moded" my ECU, so I bought another ECU and fixed the connections, and tryed it again... and another computer went to the dirt...
I really didnt believe plugging the OMP into your TPS connector would break it to where it would keep frying ECU's..
I always just thought it was an ECU problem...
After 2 computers I know now...
01-06-08, 08:12 PM
#53
Junior Member
Join Date: Feb 2007
Location: shreveport
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
having problems
Running w/o OMP injection for a short while will not affect engine health, other than perhaps a slight temporary drop in compression due to less of a coating of oil on the housing walls. Actual seal wear in the short term is negligible. Now, over a long term, this would definitely be a concern.
You can easily remove the OMP from the engine while in the car, and not damage the OMP lines. Gently bend all 4 of them back out of the way.
You can easily remove the OMP from the engine while in the car, and not damage the OMP lines. Gently bend all 4 of them back out of the way.
03-28-08, 03:17 PM
#55
This thread was pointed out to me by Blackball7. Great info. Alot better than the FSM.
From the pics of the ecu, it looks like the resister will show burn marks if it gets fried. I'm going to look up the driver chip and see if I can find some info to test it out to see if can be detected if it is "out-of-order". Working as a electronics tester/calibrator FTW!
Thread should get archived IMO.
From the pics of the ecu, it looks like the resister will show burn marks if it gets fried. I'm going to look up the driver chip and see if I can find some info to test it out to see if can be detected if it is "out-of-order". Working as a electronics tester/calibrator FTW!
Thread should get archived IMO.
03-28-08, 05:10 PM
#56
Senior Member
iTrader: (1)
Join Date: Aug 2007
Location: Indiana
Posts: 526
Likes: 0
Received 0 Likes
on
0 Posts
ok i just found some stuff out.
if the omp step motor itself fails it will not kill the ecu. to check to see if it is the step motor unplug the 6 pin connector and start the car. if it doesnt go straight into limp mode then there is your problem.
i have not found why or how this fails yet. still doing research.
if the omp step motor itself fails it will not kill the ecu. to check to see if it is the step motor unplug the 6 pin connector and start the car. if it doesnt go straight into limp mode then there is your problem.
i have not found why or how this fails yet. still doing research.
03-29-08, 07:21 PM
#57
Completely Stock
Thread Starter
Join Date: Dec 2007
Location: West Coast FL
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
MOP Failure Modes
Just wanted to relay what happened in my case. First, the original CEL failure occurred and I did read out an Error Code. I believe it was for the MOP. However, after clearing the codes and driving the car then attempting to read the codes again to verify, I never got any more codes displayed even when intentionally pulling (unconnecting) other sensors.
This led me to believe that something was wrong with my N370 ECU. However, when inspecting the ECU internals the first time nothing appeared burned. Later, after some time I checked the ECU internals again. This time I did visibly see burned components (see the photos in this thread).
In addition after checking the MOP according to the FSM specs my MOP measured within specs but it did have an internal short. This short did ultimately cause a short within my ECU.
As was previously mentioned in this thread an others, if you have an MOP Error Code being displayed:
1) Check the MOP according to the FSM and the Table I created in this thread.
2) Replace the MOP then check your ECU for damage by driving. It should not go into "limp home" Mode and there should be no CEL.
3) If there is still a CEL with good MOP then your ECU must be repaired or replaced.
This led me to believe that something was wrong with my N370 ECU. However, when inspecting the ECU internals the first time nothing appeared burned. Later, after some time I checked the ECU internals again. This time I did visibly see burned components (see the photos in this thread).
In addition after checking the MOP according to the FSM specs my MOP measured within specs but it did have an internal short. This short did ultimately cause a short within my ECU.
As was previously mentioned in this thread an others, if you have an MOP Error Code being displayed:
1) Check the MOP according to the FSM and the Table I created in this thread.
2) Replace the MOP then check your ECU for damage by driving. It should not go into "limp home" Mode and there should be no CEL.
3) If there is still a CEL with good MOP then your ECU must be repaired or replaced.
04-08-08, 09:19 AM
#58
Senior Member
iTrader: (1)
Join Date: Aug 2007
Location: Indiana
Posts: 526
Likes: 0
Received 0 Likes
on
0 Posts
i got a question for all you electrical guys out there.
ok, by now we all know that the omp will fry the ecu, but it only fries the omp area of it. now here is my question, if i put the rtek chip in the ecu would it work with a fried ecu since that part of the ecu is no longer used anymore anyways?
i got a new omp and that didnt fix it so i just want to stop spending so much money experimenting with **** and just fix it for good.
ok, by now we all know that the omp will fry the ecu, but it only fries the omp area of it. now here is my question, if i put the rtek chip in the ecu would it work with a fried ecu since that part of the ecu is no longer used anymore anyways?
i got a new omp and that didnt fix it so i just want to stop spending so much money experimenting with **** and just fix it for good.
04-08-08, 05:01 PM
#59
Completely Stock
Thread Starter
Join Date: Dec 2007
Location: West Coast FL
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
Damaged MOP Driver
This question is similar to one of my original questions in this thread. I originally was wondering "Why the (damaged) N370 ECU did not display Error Codes after the MOP (winding short) failure and damaging the ECU Driver.
I honestly don't know why or how that output device somehow affected the program execution for the Error Code display (preventing any code display). The internal ECU damage did not keep the car from running and did give the CEL after 10-15 minutes of driving with a very light foot on the gas or immediately under heavy load (boost required).
After replacing the MOP driver IC and other damaged components (an R and a C) my ECU acted completely normal for me.
So if the damaged MOP driver was removed (cut out from the PCB) and another program chip (EPROM) was installed that did not require the MOP to operate, it seems that it should work, but that is only an educated guess.
I would try and replace the "bad" MOP driver first before changing out the EPROM. However, if you have another EPROM (that doesn't care about the MOP outputs and inputs) available then it might also work. If it doesn't, you should carefully cut out the bad MOP driver and try again.
I honestly don't know why or how that output device somehow affected the program execution for the Error Code display (preventing any code display). The internal ECU damage did not keep the car from running and did give the CEL after 10-15 minutes of driving with a very light foot on the gas or immediately under heavy load (boost required).
After replacing the MOP driver IC and other damaged components (an R and a C) my ECU acted completely normal for me.
So if the damaged MOP driver was removed (cut out from the PCB) and another program chip (EPROM) was installed that did not require the MOP to operate, it seems that it should work, but that is only an educated guess.
I would try and replace the "bad" MOP driver first before changing out the EPROM. However, if you have another EPROM (that doesn't care about the MOP outputs and inputs) available then it might also work. If it doesn't, you should carefully cut out the bad MOP driver and try again.
04-08-08, 08:27 PM
#60
Ban Peak
iTrader: (49)
This question is similar to one of my original questions in this thread. I originally was wondering "Why the (damaged) N370 ECU did not display Error Codes after the MOP (winding short) failure and damaging the ECU Driver.
I honestly don't know why or how that output device somehow affected the program execution for the Error Code display (preventing any code display). The internal ECU damage did not keep the car from running and did give the CEL after 10-15 minutes of driving with a very light foot on the gas or immediately under heavy load (boost required).
After replacing the MOP driver IC and other damaged components (an R and a C) my ECU acted completely normal for me.
So if the damaged MOP driver was removed (cut out from the PCB) and another program chip (EPROM) was installed that did not require the MOP to operate, it seems that it should work, but that is only an educated guess.
I would try and replace the "bad" MOP driver first before changing out the EPROM. However, if you have another EPROM (that doesn't care about the MOP outputs and inputs) available then it might also work. If it doesn't, you should carefully cut out the bad MOP driver and try again.
I honestly don't know why or how that output device somehow affected the program execution for the Error Code display (preventing any code display). The internal ECU damage did not keep the car from running and did give the CEL after 10-15 minutes of driving with a very light foot on the gas or immediately under heavy load (boost required).
After replacing the MOP driver IC and other damaged components (an R and a C) my ECU acted completely normal for me.
So if the damaged MOP driver was removed (cut out from the PCB) and another program chip (EPROM) was installed that did not require the MOP to operate, it seems that it should work, but that is only an educated guess.
I would try and replace the "bad" MOP driver first before changing out the EPROM. However, if you have another EPROM (that doesn't care about the MOP outputs and inputs) available then it might also work. If it doesn't, you should carefully cut out the bad MOP driver and try again.
I just put a reman in my GTUs and it would start, run for about 10 seconds then die. It threw a code for the MOP. I did most of the test in the FSM, resistance, continuity in the harness etc. The stepper motor R's were good, so I truned to the ECU, sure enough it was burnt. I pulled it out and replaced it with one from a friends car. It burnt that one up.
I then ordered a brand new OMP from mazda, put it in and replaced the ECU with a good one.
No problems anymore, it runs great now.
04-16-08, 01:32 PM
#63
Junior Member
Join Date: Dec 2007
Location: Georgia
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
OK... here is the latest update of my problem...
My RX7 kept going into limp mode so i changed out my MOP, ECU and TPS with ones i knew that worked. My MOP was bad and cleared my MOP error codes, but my car was still going into limp mode.
I was getting Limp mode with no stored engine codes.
I was Dazed and confused...
I later notided that when I would drive it hard in limp mode, smoke was comming out of my gear box... I now had an exhaust leak.
I changed out my exhaust and my car was running great.... Then 5 minutes later back in limp mode...
I found it strange that limp mode would cause my engine to backfire like it did and blow my exhaust... so I did some more reading... they I found it.
My ACV was faulty. it wasn't getting the propper compression it needed due to a broken spring. As a result, It wasn't sending air to the secondary injectors.
I changed out the Valve and everything is working fine now.
My RX7 kept going into limp mode so i changed out my MOP, ECU and TPS with ones i knew that worked. My MOP was bad and cleared my MOP error codes, but my car was still going into limp mode.
I was getting Limp mode with no stored engine codes.
I was Dazed and confused...
I later notided that when I would drive it hard in limp mode, smoke was comming out of my gear box... I now had an exhaust leak.
I changed out my exhaust and my car was running great.... Then 5 minutes later back in limp mode...
I found it strange that limp mode would cause my engine to backfire like it did and blow my exhaust... so I did some more reading... they I found it.
My ACV was faulty. it wasn't getting the propper compression it needed due to a broken spring. As a result, It wasn't sending air to the secondary injectors.
I changed out the Valve and everything is working fine now.
04-30-08, 05:30 PM
#64
I had some input regarding the MOP electrical testing that I described before. In order to clear things up and make a useful tool. I created the table below with all the measurements and expected values for anyone's use. It is complete and will not lead you down the wrong path like the 1990 FSM.
Question: Is there any way to tell if your ecu is damaged before installing a properly tested functioning MOP? And, will a damaged ECU harm a MOP?
And, what is the difference between and imput device code (27) and an output device code (26)?
Trying to approach this carefully. I appreciate the work reflected in this thread.
Jack
04-30-08, 09:10 PM
#65
Senior Member
iTrader: (1)
Join Date: Aug 2007
Location: Indiana
Posts: 526
Likes: 0
Received 0 Likes
on
0 Posts
i can see some very, very light shading there but it might just be my eyes though.
im not sure besides the visual effects that may happen to an ecu but i do believe a bad ecu will burn out a good omp.
not to sure about the other stuff either.
i have not gotten enough money for this damn chip yet so i do not know if it works on a bad ecu yet. (damn brakes went out on me...) but as soon as i get it in i will inform all!
im not sure besides the visual effects that may happen to an ecu but i do believe a bad ecu will burn out a good omp.
not to sure about the other stuff either.
i have not gotten enough money for this damn chip yet so i do not know if it works on a bad ecu yet. (damn brakes went out on me...) but as soon as i get it in i will inform all!
05-01-08, 09:26 AM
#66
Ok, here is where I am. My S5 vert went into limpmode. I had 20,26,27 cel codes.
I found this thread in a search. I bought a claimed good MOP. I tested said MOP per the chart, tested good. The harness (short harness) tested good for continuity. Installed MOP, now I have #26.
I'm pretty unhappy with the situation at this point. Part swapping with 18 year old parts is ridiculous and frustrating.
Where do I go from here? Is my ecu fried? Can I test the ECU or do I have to just do a visual on the circuit board?
Started my own thread as well. https://www.rx7club.com/showthread.p...06#post8150706
I found this thread in a search. I bought a claimed good MOP. I tested said MOP per the chart, tested good. The harness (short harness) tested good for continuity. Installed MOP, now I have #26.
I'm pretty unhappy with the situation at this point. Part swapping with 18 year old parts is ridiculous and frustrating.
Where do I go from here? Is my ecu fried? Can I test the ECU or do I have to just do a visual on the circuit board?
Started my own thread as well. https://www.rx7club.com/showthread.p...06#post8150706
05-11-08, 01:17 AM
#68
Followup:
Followup:
I got a known good ecu from a good friend. The MOP tested good per the FSM+1990TurboII-75K test protocol.
Tested the TPS because Blackball7 and Dennis blackistone warned that it could be a problem as well. Both TPS tested fine,
Car works fine, I have an engine air thermosensor, code 11 cel showing up. Shouldn't be a problem but I just want to thank all involved helping.
I am still considering conversion to S4 because for the first time in 4 years, the car feels frail to me. I don't want to have this happen again.
Thanks to all for all the help.
Jack
I got a known good ecu from a good friend. The MOP tested good per the FSM+1990TurboII-75K test protocol.
Tested the TPS because Blackball7 and Dennis blackistone warned that it could be a problem as well. Both TPS tested fine,
Car works fine, I have an engine air thermosensor, code 11 cel showing up. Shouldn't be a problem but I just want to thank all involved helping.
I am still considering conversion to S4 because for the first time in 4 years, the car feels frail to me. I don't want to have this happen again.
Thanks to all for all the help.
Jack
05-13-08, 03:11 PM
#69
Noobish
Join Date: Apr 2008
Location: Louisville, KY
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
Awesome thread.
I am having the limp mode issues. My car limps after 4500 in 2-5 gears. It will backfire on occasion. I get a pulsing idle, and when the car is warm I can get that to stop by loading the engine with the clutch untill it almost dies and it will then idle between 800-1000. The car is a 90 vert, with a replacement 89 na motor (not sure of model it came from as it was as is when I purchased it.
My ecu is fried. The .1 resistor and Toshiba MP4501 are badly burned just like the pic shows. I tested the mop on car and it tests OK except for the infinite tests. I do not get a reading with my dmm when trying the infinite tests. Maybe idk how to get a reading there.
I was told that the mop was bad when I bought the car so I got 2 off ebay, 1 tested good, 1 tested bad, so I have a spare mop. I haven't tested the tps as of yet.
I have found the .1 resistor and Toshiba MP4501 online for $10 and I am considering fixing the ecu. Is that a good idea?
Any other possible causes/soultions?
Any help reading infitite ohms?
Thanks in advance!
05-23-08, 03:59 PM
#71
Completely Stock
Thread Starter
Join Date: Dec 2007
Location: West Coast FL
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
Thread
Thread Starter
Forum
Replies
Last Post
Adaptronic 1280s Hot Start 3 Rotor 20b RX7
Monsterbox
Adaptronic Engine Mgmt - AUS
5
09-11-15 03:29 PM
rx8volks
Canadian Forum
0
09-01-15 11:02 PM
