Need help solving this one
10-15-2017, 08:53 PM
#1
Newbie - Just Registered
Thread Starter
Join Date: Oct 2017
Posts: 6
Need help solving this one
Hey everybody, Thanks in advance for any help you give. Ill try to give as much information as I can.
1. My alternator went out. I was quite a ways from home to I had to drive it until the battery went dead, and I had it towed the rest of the way.
2. I replaced the Alternator, started the car and showed 14v at the battery. The next day I started the car and the alt was not working again. I took back out and up to Autozone to have it tested, it was good.I started checking fuses and noticed that i had a blown eng mgt fuse. both sides terminals showed 12v(short somewhere) I tried looking it up but couldn't find out what that fuse did. to many conflicting answers. I noticed that my battery wasn't holding a charge, so i took it to have it tested and it was bad.
3. I replaced the battery, put everything back together and boom...14v at the battery. not sure how a bad battery cause the alt not to at least show it was charging, but hey, it worked. the eng mgt fuse was still shorted, but everything seemed to work.
4. i drove the car aroung town for 2wks with no issues.
5. I took a trip out of town, about 400miles into it my belt broke. it was 1am and had to be in Ny in the morning and still had about 450 miles to go so i went to the nearest walamrt and picked up 3 batteries so i could just swap them out as they went dead so i could at least get there. Luckly all i lost was a/c and alt. about 350-400 miles later i lost engine power. the car started to just slow down. no matter how much gas i gave it, the rpm's wouldn't move. I was able to get pulled over and check the CEL, and got a p1605. Comm failure between the ECU and TCM. I had to get towed the rest of the way....$$$$$$$. I ran the Transmission self test from the service manual. Im not sure if i did it right or not because the o/d light just stayed on, which to me either means i did it wrong or from the SM, PNP switch, o/d control switch or throttle position circuit is dissconnected, or TCM is bad. Because of the P1605 code i ordered another TCM.
6. I replaced the belt, and ordered another TCM. installed both, and took the car for a test drive. It seemed to drive fine for a few miles, then the same issues. when it first started it would just take off slow and very slowly build up speed, but because of the speed limits in NYC i never really got over 40. after that i ran the Self test again, and it didn't seem to match any of the options in the SM.
7. I swapped the TCM back to my original, just to test it again. it seemed to be worse than with the other TCM. When i first started driving, it was like the other time, very slow to take off and would very slowly build up speed, then it got much worse.i could floor it and the rpms don't move. it wouldn't go over 10 mph. Then i figured out i could pump the gas over and over, not stopping, and i could get it up to about 30, just continually pumping the gas. I was about 10 miles from where I had to be do i didn't really have a choice to get it back. after that i ran the Self test again, i recorded it and linked the youtube video for other to verify. To me it is from the SM "all judgement flickers are the same" from the SM it looks like there is suppose to be one long flicker first, then the 10 judgement flickers. and if they are all the same, which that is how it looks to me, that is "all circuits that can be confirmed by self diagnosis are ok"
Thats where I am. I have also read that the P1605 code means the ECU is actually the problem. any thoughts or ideas would be awesome. I'm kind stuck on what to do. Im about 900 miles from home so dropping it off at a shop isn't really going to happen. at best I will fly home and come back to get it with a trailer. But I would love to be able to fix it here. Should I repace the ECU?
Thanks Guys
1. My alternator went out. I was quite a ways from home to I had to drive it until the battery went dead, and I had it towed the rest of the way.
2. I replaced the Alternator, started the car and showed 14v at the battery. The next day I started the car and the alt was not working again. I took back out and up to Autozone to have it tested, it was good.I started checking fuses and noticed that i had a blown eng mgt fuse. both sides terminals showed 12v(short somewhere) I tried looking it up but couldn't find out what that fuse did. to many conflicting answers. I noticed that my battery wasn't holding a charge, so i took it to have it tested and it was bad.
3. I replaced the battery, put everything back together and boom...14v at the battery. not sure how a bad battery cause the alt not to at least show it was charging, but hey, it worked. the eng mgt fuse was still shorted, but everything seemed to work.
4. i drove the car aroung town for 2wks with no issues.
5. I took a trip out of town, about 400miles into it my belt broke. it was 1am and had to be in Ny in the morning and still had about 450 miles to go so i went to the nearest walamrt and picked up 3 batteries so i could just swap them out as they went dead so i could at least get there. Luckly all i lost was a/c and alt. about 350-400 miles later i lost engine power. the car started to just slow down. no matter how much gas i gave it, the rpm's wouldn't move. I was able to get pulled over and check the CEL, and got a p1605. Comm failure between the ECU and TCM. I had to get towed the rest of the way....$$$$$$$. I ran the Transmission self test from the service manual. Im not sure if i did it right or not because the o/d light just stayed on, which to me either means i did it wrong or from the SM, PNP switch, o/d control switch or throttle position circuit is dissconnected, or TCM is bad. Because of the P1605 code i ordered another TCM.
6. I replaced the belt, and ordered another TCM. installed both, and took the car for a test drive. It seemed to drive fine for a few miles, then the same issues. when it first started it would just take off slow and very slowly build up speed, but because of the speed limits in NYC i never really got over 40. after that i ran the Self test again, and it didn't seem to match any of the options in the SM.
7. I swapped the TCM back to my original, just to test it again. it seemed to be worse than with the other TCM. When i first started driving, it was like the other time, very slow to take off and would very slowly build up speed, then it got much worse.i could floor it and the rpms don't move. it wouldn't go over 10 mph. Then i figured out i could pump the gas over and over, not stopping, and i could get it up to about 30, just continually pumping the gas. I was about 10 miles from where I had to be do i didn't really have a choice to get it back. after that i ran the Self test again, i recorded it and linked the youtube video for other to verify. To me it is from the SM "all judgement flickers are the same" from the SM it looks like there is suppose to be one long flicker first, then the 10 judgement flickers. and if they are all the same, which that is how it looks to me, that is "all circuits that can be confirmed by self diagnosis are ok"
Thats where I am. I have also read that the P1605 code means the ECU is actually the problem. any thoughts or ideas would be awesome. I'm kind stuck on what to do. Im about 900 miles from home so dropping it off at a shop isn't really going to happen. at best I will fly home and come back to get it with a trailer. But I would love to be able to fix it here. Should I repace the ECU?
Thanks Guys
10-17-2017, 10:45 PM
#2
I wouldn't replace the ECU just yet, they don't go bad that often. Also, getting the correct one is kind of difficult.
I am wondering about this "eng mgt" fuse. I am familiar with Maximas and they do not call any fuse eng mgt. Look at the fuse box and tell me the physical location, i.e., left column, middle column, right column. Then count up from the bottom of that column to the fuse. Count any empty spaces. Fo example, you might tell me middle column, 6th fuse up.
Calling the fuse shorted - you are saying the wrong things. Something that is shorted will not show a voltage. A shorted circuit will read zero volts.
The slow engine acceleration - cold be related to the fuse problem. Don't know if the car is in "limp" mode or a bad MAF. Need more info on this one. Need to figure out this fuse thing.
I am wondering about this "eng mgt" fuse. I am familiar with Maximas and they do not call any fuse eng mgt. Look at the fuse box and tell me the physical location, i.e., left column, middle column, right column. Then count up from the bottom of that column to the fuse. Count any empty spaces. Fo example, you might tell me middle column, 6th fuse up.
Calling the fuse shorted - you are saying the wrong things. Something that is shorted will not show a voltage. A shorted circuit will read zero volts.
The slow engine acceleration - cold be related to the fuse problem. Don't know if the car is in "limp" mode or a bad MAF. Need more info on this one. Need to figure out this fuse thing.
10-18-2017, 04:11 PM
#3
Newbie - Just Registered
Thread Starter
Join Date: Oct 2017
Posts: 6
Thanks for the help. The fuse is on the left side, 4th fuse down from the 120amp battery fuse. It is labeled eng mtg.
The fuse has been like that, showing 12v on both sides with the engine off and fuse pulled, for a little while now. I just had the problem with the car not moving the other day. Thanks for the continued help
The fuse has been like that, showing 12v on both sides with the engine off and fuse pulled, for a little while now. I just had the problem with the car not moving the other day. Thanks for the continued help
10-18-2017, 11:42 PM
#4
OK, thanks for the info. The Maxima does not have that fuse, it is an empty spot. In the Maxima they tap into another fuse rather than put in a separate fuse. Interesting. Anyway...
That fuse is for the front motor mount by the radiator. Nissan/Infiniti calls it the Electronic Controlled Mounting. The motor mount is a variable stiffness device to reduce vibrations from the engine from transferring into the frame of the car. To accomplish this, the motor mount is a bag of oil. To make it softer, oil is pumped out. To make it firmer, oil is pumped in. The motor mount is self contained with its own oil reservoir and pump that is operated by a small electric motor. When engine rpm is below 1,000, the motor mount is soft. Over 1,000 rpm, the motor mount is stiff.
As for the fuse, it should have 12 volts on one side all the time as it is wired directly to the battery. But when the fuse is pulled out, I would expect the other side that goes to the electric motor of the motor mount to be nothing/zero. I don't know why you measure 12 volts.
These motor mounts do go bad in one of 2 ways. The rubber bladder might rupture and all the oil leaks out and the motor mount can no longer change stiffness. The other was it goes bad is that the electric motor shorts out. This is bad as it usually causes an integrated circuit (STA509A) in the ECU to physically burn up. If that were to be all that happens, it would be an easy fix. But many times when the transistor burns up, it also damages the printed circuit board and other things may not work.
Has this happened to you? I don't know. There is a diagnostic procedure in the FSM.
See page 527 - http://boredmder.com/FSMs/Infiniti/I30/1999/EC.pdf
To see if the STA509A transistor in the ECU has burned up, you would have to pull the ECU out, open it up and look.
Here is a link from the Maxima threads with photos showing damaged ECUs. Scroll sown to post # 51 for a photo. There are more photos if you care to look through the whole thread.
https://maxima.org/forums/5th-genera...seconds-2.html
If you have a a damaged ECU, there are repair services that you can send the ECU to. The prices vary from $150 to $250. You would get your ECU back in 3 - 4 days. Repair has advantages over replacing. Repair is usually cheaper. You keep the same ECU with the proper options and you have to get your keys re-programmed.
I still don't have any better idea as to what is wrong with the car. This may be a drawn out step by step process. Check the ECU for damage and we'll go from there.
That fuse is for the front motor mount by the radiator. Nissan/Infiniti calls it the Electronic Controlled Mounting. The motor mount is a variable stiffness device to reduce vibrations from the engine from transferring into the frame of the car. To accomplish this, the motor mount is a bag of oil. To make it softer, oil is pumped out. To make it firmer, oil is pumped in. The motor mount is self contained with its own oil reservoir and pump that is operated by a small electric motor. When engine rpm is below 1,000, the motor mount is soft. Over 1,000 rpm, the motor mount is stiff.
As for the fuse, it should have 12 volts on one side all the time as it is wired directly to the battery. But when the fuse is pulled out, I would expect the other side that goes to the electric motor of the motor mount to be nothing/zero. I don't know why you measure 12 volts.
These motor mounts do go bad in one of 2 ways. The rubber bladder might rupture and all the oil leaks out and the motor mount can no longer change stiffness. The other was it goes bad is that the electric motor shorts out. This is bad as it usually causes an integrated circuit (STA509A) in the ECU to physically burn up. If that were to be all that happens, it would be an easy fix. But many times when the transistor burns up, it also damages the printed circuit board and other things may not work.
Has this happened to you? I don't know. There is a diagnostic procedure in the FSM.
See page 527 - http://boredmder.com/FSMs/Infiniti/I30/1999/EC.pdf
To see if the STA509A transistor in the ECU has burned up, you would have to pull the ECU out, open it up and look.
Here is a link from the Maxima threads with photos showing damaged ECUs. Scroll sown to post # 51 for a photo. There are more photos if you care to look through the whole thread.
https://maxima.org/forums/5th-genera...seconds-2.html
If you have a a damaged ECU, there are repair services that you can send the ECU to. The prices vary from $150 to $250. You would get your ECU back in 3 - 4 days. Repair has advantages over replacing. Repair is usually cheaper. You keep the same ECU with the proper options and you have to get your keys re-programmed.
I still don't have any better idea as to what is wrong with the car. This may be a drawn out step by step process. Check the ECU for damage and we'll go from there.
10-19-2017, 03:04 AM
#5
Newbie - Just Registered
Thread Starter
Join Date: Oct 2017
Posts: 6
Thanks a lot. That is great information. I have been trying to figure out what that fuse does for a while now. I have finally given up on the car myself and dropped it off at the shop yesterday. I'll check that out when I get it back and let you know
Thanks again
Thanks again
11-15-2017, 07:25 AM
#6
Newbie - Just Registered
Thread Starter
Join Date: Oct 2017
Posts: 6
i got the car back from the shop. They where no help. So now, everything runs fine until it come up to temp, it starts to get worse. first it starts to shift a little hard, then eventually when i push the gas, the car acts like i'm not. i can floor it, no increase in rpm's nothing. no cec.
11-17-2017, 09:30 AM
#7
I don't know if this is it, but your symptoms are starting to fall in line with a bad MAF. With a bad MAF, the engine will have no power and the engine rpms will be restricted to 2500. As the MAF gets worse, the engine will die out and eventually you will not be able to start the engine. The only thing that does fit is the transmission shifting thing.
11-18-2017, 06:23 AM
#9
Newbie - Just Registered
Thread Starter
Join Date: Oct 2017
Posts: 6
I was wrong about that fuse we where talking about before. it is the 5th fuse down, labeled ENG MTG (linked picture). its showing battery voltage on the correct side, and o volts on the other, but still blows the fuse as soon as i put it in. as for the MAF sensor, i did all the test in the service manual and its good.
https://www.dropbox.com/s/29ihij6kuq...75212.jpg?dl=0
https://www.dropbox.com/s/29ihij6kuq...75212.jpg?dl=0
