Engine control 2 fuse blowing - I'm going crazy
06-17-2019, 04:06 PM
#1
Junior Member
Thread Starter
Join Date: Jan 2014
Location: Brunswick, Maine
Posts: 29
Engine control 2 fuse blowing - I'm going crazy
Hey guys,
So, I leave work today, drive my 02 maxima 6 speed w/ 206k on it roughly a half mile, and it dies. It still cranks, but won't fire. Fast forward, I'm home, searching every forum I can find, and going absolutely insane.
The other forums I've read regarding engine control 2, the fuse blows when you turn the key on. Mine is different. The keys are not even in the car (but battery still connected obviously), and the fuse instantaneously blows. I don't believe it's NATS or the immobilizer, but I'm not sure. The red security LED doesn't come on whatsoever now (it used to when I locked the car). I've unplugged everything I can get my hands on. 5 Coils, 3 injectors, TB, all o2 sensors, MAF sensor, any other random connector I can see, and burnt through roughly 25 fuses thus far trying to test everything I can think of. I even pulled the Engine Control relay in front of the battery out, and it still blew. There's nothing I've done that hasn't made it blow. The whole reason I looked at the eng cont 2 was because I tried to pull codes when first troubleshooting, only to find, strange, I can't reach my ECU for some reason. That's when I found this horrible horrible fuse. Engine light won't come on. Security light won't come on. Can someone please help me before I light the damn thing on fire?
I haven't checked the actual ECU to see if anything is fried inside, or the NATS. Where are these two located? ANY help would be greatly appreciated. No new work has been done on the vehicle in a long time (I replaced the struts a few months back) that's it. I'm losing my mind. Thanks in advance for any help.
So, I leave work today, drive my 02 maxima 6 speed w/ 206k on it roughly a half mile, and it dies. It still cranks, but won't fire. Fast forward, I'm home, searching every forum I can find, and going absolutely insane.
The other forums I've read regarding engine control 2, the fuse blows when you turn the key on. Mine is different. The keys are not even in the car (but battery still connected obviously), and the fuse instantaneously blows. I don't believe it's NATS or the immobilizer, but I'm not sure. The red security LED doesn't come on whatsoever now (it used to when I locked the car). I've unplugged everything I can get my hands on. 5 Coils, 3 injectors, TB, all o2 sensors, MAF sensor, any other random connector I can see, and burnt through roughly 25 fuses thus far trying to test everything I can think of. I even pulled the Engine Control relay in front of the battery out, and it still blew. There's nothing I've done that hasn't made it blow. The whole reason I looked at the eng cont 2 was because I tried to pull codes when first troubleshooting, only to find, strange, I can't reach my ECU for some reason. That's when I found this horrible horrible fuse. Engine light won't come on. Security light won't come on. Can someone please help me before I light the damn thing on fire?
I haven't checked the actual ECU to see if anything is fried inside, or the NATS. Where are these two located? ANY help would be greatly appreciated. No new work has been done on the vehicle in a long time (I replaced the struts a few months back) that's it. I'm losing my mind. Thanks in advance for any help.
06-18-2019, 08:13 AM
#3
Junior Member
Thread Starter
Join Date: Jan 2014
Location: Brunswick, Maine
Posts: 29
After continuing research on the forums and FSMs, I seem to be in the same situation as EddieBob was, but no one ever responded to his question. He wrote:
"Pull out the service manual and followed the steps for No Power to ECM. I've found that one of the 15A fuses is blown because the ECM relay is not getting power. When I put a new fuse in, with the ECM relay still disconnected, it blows the fuse right away. Manual says check joint connected 12 or open short between fuse box and ECM Relay. Anyone knows where the joint 12 connector is at or have dealt with this issue before?"
From the FSM it shows the joint connector 12 over in the passenger side relay box? Does anyone know if this is true? Why would the connector for the ECM relay and fuse block be on the opposite side of the car? ANY help would be greatly appreciated.
"Pull out the service manual and followed the steps for No Power to ECM. I've found that one of the 15A fuses is blown because the ECM relay is not getting power. When I put a new fuse in, with the ECM relay still disconnected, it blows the fuse right away. Manual says check joint connected 12 or open short between fuse box and ECM Relay. Anyone knows where the joint 12 connector is at or have dealt with this issue before?"
From the FSM it shows the joint connector 12 over in the passenger side relay box? Does anyone know if this is true? Why would the connector for the ECM relay and fuse block be on the opposite side of the car? ANY help would be greatly appreciated.
06-18-2019, 11:10 AM
#4
Hey guys,
So, I leave work today, drive my 02 maxima 6 speed w/ 206k on it roughly a half mile, and it dies. It still cranks, but won't fire. Fast forward, I'm home, searching every forum I can find, and going absolutely insane.
The other forums I've read regarding engine control 2, the fuse blows when you turn the key on. Mine is different. The keys are not even in the car (but battery still connected obviously), and the fuse instantaneously blows. I don't believe it's NATS or the immobilizer, but I'm not sure. The red security LED doesn't come on whatsoever now (it used to when I locked the car). I've unplugged everything I can get my hands on. 5 Coils, 3 injectors, TB, all o2 sensors, MAF sensor, any other random connector I can see, and burnt through roughly 25 fuses thus far trying to test everything I can think of. I even pulled the Engine Control relay in front of the battery out, and it still blew. There's nothing I've done that hasn't made it blow. The whole reason I looked at the eng cont 2 was because I tried to pull codes when first troubleshooting, only to find, strange, I can't reach my ECU for some reason. That's when I found this horrible horrible fuse. Engine light won't come on. Security light won't come on. Can someone please help me before I light the damn thing on fire?
I haven't checked the actual ECU to see if anything is fried inside, or the NATS. Where are these two located? ANY help would be greatly appreciated. No new work has been done on the vehicle in a long time (I replaced the struts a few months back) that's it. I'm losing my mind. Thanks in advance for any help.
So, I leave work today, drive my 02 maxima 6 speed w/ 206k on it roughly a half mile, and it dies. It still cranks, but won't fire. Fast forward, I'm home, searching every forum I can find, and going absolutely insane.
The other forums I've read regarding engine control 2, the fuse blows when you turn the key on. Mine is different. The keys are not even in the car (but battery still connected obviously), and the fuse instantaneously blows. I don't believe it's NATS or the immobilizer, but I'm not sure. The red security LED doesn't come on whatsoever now (it used to when I locked the car). I've unplugged everything I can get my hands on. 5 Coils, 3 injectors, TB, all o2 sensors, MAF sensor, any other random connector I can see, and burnt through roughly 25 fuses thus far trying to test everything I can think of. I even pulled the Engine Control relay in front of the battery out, and it still blew. There's nothing I've done that hasn't made it blow. The whole reason I looked at the eng cont 2 was because I tried to pull codes when first troubleshooting, only to find, strange, I can't reach my ECU for some reason. That's when I found this horrible horrible fuse. Engine light won't come on. Security light won't come on. Can someone please help me before I light the damn thing on fire?
I haven't checked the actual ECU to see if anything is fried inside, or the NATS. Where are these two located? ANY help would be greatly appreciated. No new work has been done on the vehicle in a long time (I replaced the struts a few months back) that's it. I'm losing my mind. Thanks in advance for any help.
Do you have Mice nests in your car . That could be the work done on your car. And stop putting fuses in,that will only make it worse.
Are you getting any codes?
06-19-2019, 02:37 AM
#6
Junior Member
Thread Starter
Join Date: Jan 2014
Location: Brunswick, Maine
Posts: 29
Here's the latest update:
Dennis,
I left the battery unhooked last night in hopes it may reset the ECU and something would change. Well, I started out with the multimeter and tested where the ECM relay sits for power, and it was getting ~12.6v (between locations 2 & 6 as it states in the manual). Therefore, just for gigs, I swapped the Radiator Fan 3 relay with the ECM relay, just to make sure the relay wasn't the culprit. I also went ahead and unplugged the two IVBC1 & 2 since I had never checked those previously. I slapped in a fuse, and, to my surprise, it didn't blow. I thought no way. So, I plugged in the IVBCs one at a time, fuse still didn't blow. I had previously swapped the ecm relay with no change, so I didn't think swapping it with the radiator fan 3 relay would change anything. Anyways, I started the car up, and it ran great, and I could actually see my CEL inside the car. I ran it for roughly 30 seconds or so (very excited) and then shut it off thinking I was all set and wanted to get tools out of the engine bay and wrap up any loose covers or connections. Wrapped everything up, got back in the car, no CEL, and the car wouldn't start. Checked Eng Cont 2 fuse, blown again. Tried changing relays again, nothing. Tried unplugging the IVBCs again, nothing, blown fuses. Therefore I was thinking, did leaving the car unhooked from the battery overnight allow me to start the car since the ECU was reset? (I'll test again tonight since I left the battery unhooked again). My other thought, I pulled the base of the ECM relay out of the plastic holder it sits in so I could turn it upside down and check/verify the wires/connections. They all seem tight, but they are all corroded. The green corrosion was all inside the base of the relay and covering most of the electrical connections on the wires inside. Do you think this has something to do with it? Could that cause a short? The fuse blew again whether the relay was installed or not, just like before. I guess the good news is I know the ECU and NATS are not the culprit (I think...) I'm leaning towards a short somewhere between the ECM relay and the fuse box. What do you think? Thanks for any help!!!
Zach
To answer your questions, Krismax, there's no evidence of mice anywhere, and you can't pull codes due to the fact that you can't reach the ECU...
Originally Posted by DennisMik
This fuse is referenced for 11 electrical circuits.
The schematics & page number are:
ECM/PW - EC 460 - to pin 67 of ECM
EMNT - EC 734 - to front & rear elect engine mounts (auto trans cars)
IGNSYS - EC 706 - to ECM relay coil & n/o contacts
IVCB1 - EC - Intake Valve Timing Control solenoid Bank 1
IVCB2 - EC - Intake Valve Timing Control solenoid Bank 2
MAFS - EC 189 - to ECM relay coil & n/o contacts
EC 195 - same as above
EC 465 - same as above
MAIN - EC 155 - to ECM relay coil & n/o contacts
NATS - EL 358 - Thru joint connector to pin 8 of NVIS IMMU
PGC/V - EC 376 - to ECM relay coil & n/o contacts
EC 589 - same as above
PHASE - EC 337 - to ECM relay coil & n/o contacts
POS - EC 330 - to ECM relay coil & n/o contacts
Looking at page EC155, you have the fuse identified correctly. As for the wires going over to the passenger side, that is evidently correct also. While it seems stupid, that's the way it was done. It isn't worth killing brain cells trying to understand. Sometimes I think some of this was done by aliens. Or it just may be that it is because you have a Japanese car company owned by a French company.
With the fuse still blowing with the ECM relay removed could indicate that there is a short in the wire harness between the fuse and somewhere, this is not 100% guaranteed. The service manual references 11 circuits (see above) where fuse 59 ENG CONT 2 is used. Some of the connections to this fuse have to have the ECM relay energized, which would not be the case with the ignition key being turned off. Having the relay pulled out eliminates some weird problem within the relay itself.
Of the 11 circuits using this fuse, 2 of them are for the oil filled electric motor mounts. These are only on cars with an automatic transmission. So unless your car was originally automatic and converted to manual trans, you don't have these.
There is the NATS circuit that has direct power from fuse 59 going to the NATS IMMU. This is in the steering column by the ignition key lock. This could be a possibility. If this module is fubar, this may explain the security light. I forget what is normal on that.
The ECM has direct power from fuse 59 going to it on pin 67. Another possibility
.
Maybe the 2 camshaft timing solenoids may have direct power from the fuse, I am less than 50% sure of this. I need to research this more.
Joint connector 12 is the "thing" that connector E73 plugs on to. A joint connector allows a wire to be split into two or more wires.
Look on page EL-460. It shows the engine wire harness connectors. It sounds like you may have looked at it all ready.
The 2 easiest things to do would be to take the steering column cover off and unplug the NATS IMMU module and see if the fuse blows. Do the same thing with the ECM.
Dennis
Quote:
Originally Posted by zachpark17
Copy that. Thank you for the reply and any help you may be able to give me. When looking at the FSM, EC-155, I believe it's fuse 59 (top right of page) off the battery which is Eng Cont 2. This is the fuse that blows no matter what. Right below it is the Joint Connector 12 or E73. When searching the FSM it shows that JC-12 over (inside?) the relay box on the passenger side of the engine bay. This seems odd to me, as I'm confused why that fuse would run all the way over to the passenger side, just to come all the way back around to the ECM Relay right in front of the battery.
When I removed the ECM relay and installed a new fuse, it still blew instantly. Doesn't this suggest there is a short somewhere in between the battery, fuse, and relay? I'm just thinking out loud...
I was checking things out for the correct fuse and can be more intelligent on this. Here is a quick compilation of what fuse 59 is used for.Originally Posted by zachpark17
Copy that. Thank you for the reply and any help you may be able to give me. When looking at the FSM, EC-155, I believe it's fuse 59 (top right of page) off the battery which is Eng Cont 2. This is the fuse that blows no matter what. Right below it is the Joint Connector 12 or E73. When searching the FSM it shows that JC-12 over (inside?) the relay box on the passenger side of the engine bay. This seems odd to me, as I'm confused why that fuse would run all the way over to the passenger side, just to come all the way back around to the ECM Relay right in front of the battery.
When I removed the ECM relay and installed a new fuse, it still blew instantly. Doesn't this suggest there is a short somewhere in between the battery, fuse, and relay? I'm just thinking out loud...
This fuse is referenced for 11 electrical circuits.
The schematics & page number are:
ECM/PW - EC 460 - to pin 67 of ECM
EMNT - EC 734 - to front & rear elect engine mounts (auto trans cars)
IGNSYS - EC 706 - to ECM relay coil & n/o contacts
IVCB1 - EC - Intake Valve Timing Control solenoid Bank 1
IVCB2 - EC - Intake Valve Timing Control solenoid Bank 2
MAFS - EC 189 - to ECM relay coil & n/o contacts
EC 195 - same as above
EC 465 - same as above
MAIN - EC 155 - to ECM relay coil & n/o contacts
NATS - EL 358 - Thru joint connector to pin 8 of NVIS IMMU
PGC/V - EC 376 - to ECM relay coil & n/o contacts
EC 589 - same as above
PHASE - EC 337 - to ECM relay coil & n/o contacts
POS - EC 330 - to ECM relay coil & n/o contacts
Looking at page EC155, you have the fuse identified correctly. As for the wires going over to the passenger side, that is evidently correct also. While it seems stupid, that's the way it was done. It isn't worth killing brain cells trying to understand. Sometimes I think some of this was done by aliens. Or it just may be that it is because you have a Japanese car company owned by a French company.
With the fuse still blowing with the ECM relay removed could indicate that there is a short in the wire harness between the fuse and somewhere, this is not 100% guaranteed. The service manual references 11 circuits (see above) where fuse 59 ENG CONT 2 is used. Some of the connections to this fuse have to have the ECM relay energized, which would not be the case with the ignition key being turned off. Having the relay pulled out eliminates some weird problem within the relay itself.
Of the 11 circuits using this fuse, 2 of them are for the oil filled electric motor mounts. These are only on cars with an automatic transmission. So unless your car was originally automatic and converted to manual trans, you don't have these.
There is the NATS circuit that has direct power from fuse 59 going to the NATS IMMU. This is in the steering column by the ignition key lock. This could be a possibility. If this module is fubar, this may explain the security light. I forget what is normal on that.
The ECM has direct power from fuse 59 going to it on pin 67. Another possibility
.
Maybe the 2 camshaft timing solenoids may have direct power from the fuse, I am less than 50% sure of this. I need to research this more.
Joint connector 12 is the "thing" that connector E73 plugs on to. A joint connector allows a wire to be split into two or more wires.
Look on page EL-460. It shows the engine wire harness connectors. It sounds like you may have looked at it all ready.
The 2 easiest things to do would be to take the steering column cover off and unplug the NATS IMMU module and see if the fuse blows. Do the same thing with the ECM.
Dennis
Dennis,
I left the battery unhooked last night in hopes it may reset the ECU and something would change. Well, I started out with the multimeter and tested where the ECM relay sits for power, and it was getting ~12.6v (between locations 2 & 6 as it states in the manual). Therefore, just for gigs, I swapped the Radiator Fan 3 relay with the ECM relay, just to make sure the relay wasn't the culprit. I also went ahead and unplugged the two IVBC1 & 2 since I had never checked those previously. I slapped in a fuse, and, to my surprise, it didn't blow. I thought no way. So, I plugged in the IVBCs one at a time, fuse still didn't blow. I had previously swapped the ecm relay with no change, so I didn't think swapping it with the radiator fan 3 relay would change anything. Anyways, I started the car up, and it ran great, and I could actually see my CEL inside the car. I ran it for roughly 30 seconds or so (very excited) and then shut it off thinking I was all set and wanted to get tools out of the engine bay and wrap up any loose covers or connections. Wrapped everything up, got back in the car, no CEL, and the car wouldn't start. Checked Eng Cont 2 fuse, blown again. Tried changing relays again, nothing. Tried unplugging the IVBCs again, nothing, blown fuses. Therefore I was thinking, did leaving the car unhooked from the battery overnight allow me to start the car since the ECU was reset? (I'll test again tonight since I left the battery unhooked again). My other thought, I pulled the base of the ECM relay out of the plastic holder it sits in so I could turn it upside down and check/verify the wires/connections. They all seem tight, but they are all corroded. The green corrosion was all inside the base of the relay and covering most of the electrical connections on the wires inside. Do you think this has something to do with it? Could that cause a short? The fuse blew again whether the relay was installed or not, just like before. I guess the good news is I know the ECU and NATS are not the culprit (I think...) I'm leaning towards a short somewhere between the ECM relay and the fuse box. What do you think? Thanks for any help!!!
Zach
To answer your questions, Krismax, there's no evidence of mice anywhere, and you can't pull codes due to the fact that you can't reach the ECU...
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