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Discussion Starter · #1 ·
Sentra suffered from hard starts to not starting, now cranks no start. After checking compression, fuel and spark went to the fuses and pulled some for visual inspection, this includes the 34 and 36 fuses for ECM.
When I put them in and put scanner on car it gave me codes p1111 and p1065 for the first time. I figured this faulty ECM code could have been the problem all along as I've spent a bit of $$$ with two dif mechanics (fuel injectors, fuel pumps etc) a few months before this and have replaced cam and crank sensors and spark plugs myself since.
Could pulling and replacing ECM fuses caused these codes to suddenly appear?
Also checked for voltage at ECM power supply pins 119, 120 and 121. Only backup gives power of 12v while 119 and 120 read .6 and decreases from there. This test was with key on maybe I did something wrong?
Ground was good, continuity was good but am a complete novice when it comes to electrical. Lengthy post but tried to include as much info as I can. Does anyone know what this means? Thank you to anyone reading this!
 

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You may have a damaged harness, I was chasing something similar a long time ago and that was my issue.

1111 is for the IVT solenoid and 1065 is for the ecu, these to me indicate power is cut off for those items....again from my own experience. Will have to go through the harness and repair the damage.

Start in the area on the drivers side front where the harness is branches off into the fender, fuse box and to the rad.
 
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Discussion Starter · #4 ·
Hey, thank you for taking the time to reply. After pulling the fuse box up i didn't see any damage at connections.
What else should I be looking for in harness? I haven't thoroughly gone through the harness but was able to verify continuity to relay and from relay to ECM. One discrepancy was continuity from ECM to pos battery cable checked good with a test light but not with voltmeter at the 119 and 120 pins. These are the same pins reading .6 volts and lower with voltmeter, the power supply. Is that normal to get continuity but very low voltage? Battery is new and 12+ volts. Started to think ECM wiring was red herring but the low voltage has me convinced.
 

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Discussion Starter · #5 ·
What's fuel pressure at?

Good question, I never put a fuel pressure gauge on to test. I did try using starter fluid to help start the car and noticed a bit of fuel on spark plugs when trying to start the car. That was when I got the ECU code so it derailed me from thinking it was fuel related. Ready to go back to fuel being the culprit and decided to post here.
Can I take fuel pressure at firewall or does it have to be at the pump? Still wondering if those codes could have popped up as a result of removing and replacing ECU fuses.
 

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Id have to look at wiring diagrams for that. If .6v is supposed to be 12v. Thats the issue. Try swapping the main ecu relay with another similar one. Otherwise youd have to check resistance of the entire wire and narrow it down
 
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Discussion Starter · #7 ·
Ok thank you those are the wires I'm looking at now. I also switched out the ECU relay for a new one today. Continuity and resistance checked out from positive battery cable to relay and from relay to ECU. Question on how to read this diagram, does anyone know what the circled area means? The wires are connected with a dotted line
 

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You should be checking fuel pressure at the rail, if at all possible. I haven't owned a B15 in over a decade.

If you saw the plugs drenched in fuel then there's no spark.

Are those codes still present? If so, try pulling the negative battery terminal and resetting the ECU. If there was a hiccup, that'll fix it.

Does the tachometer move when you're cranking it? If not, then the ECU is not receiving a crank/cam signal. Which I don't think is the case since it didn't throw the code for it.

P1065 is concerning. Unplug and inspect the harness connectors going to the ECU. Look for any corrosion on the pins or any signs of water intrusion. Follow the harness back from there and look for snags, kinks, or bare wiring. If you have any spots on the harness that are hacked up, check there too. Verify power is going to the power pins on the harness plug, and verify the ground continuity on the ground pins. If you didn't blow any fuses I'd guess there's probably no major short.

The P1111 code is interesting. That's the variable timing control actuator. There's a possibility it could be fouled with sludge I guess. Very odd. I don't think P1111 will stop it from running though.

Reset the ECU and rescan for codes. See what's coming back. If those codes come right back and you can't any faults with the 12v supply or the ground circuit, I would lean towards ECU failure. Which surprises me because typically when ECU's shit the bed they puke out a laundry list of codes.

Get ahold of an OBD II scanner that reads out live data and see what's missing. Look for throttle position, look for the anti-theft status, look for the RPM signal (check while cranking), basically just keep your eyes open for something that doesn't look right.

Instead of chasing red herrings in the wiring, work with what the ECU is telling you. Start with P1065.
 

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Discussion Starter · #9 ·
Hey thanks for all the info, I pulled plugs and got spark on each of them a few days ago. Still baffled on why I'm getting low voltage at power supply pins for ECU but can't find any resistance in wires. Going to put ECU back in and hook everything up to see if it's still throwing those codes.
 

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Question on how to read this diagram, does anyone know what the circled area means? The wires are connected with a dotted line
The dotted line means all those wires are part of the same connector. Pins 1, 2 & 3 of connector E10 (male) and F48 (female)
 

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Do you think those codes could have been thrown by removing the ECU fuses and putting them back? Have the computer hooked up now just waiting a few minutes before I put scanner on
It's possible. One way to find out is to reset the ECU by removing the negative terminal on the battery and seeing of those codes come back.
 

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Just tossing it out there I have been through those rodeos no pulse on my Noid light cranks but no start no pump priming signal…

2005 Nissan Sentra SE had a bad ECU (fried) and related relays due to poor / insufficient grounding so - oooooooo - hhhhhhh replaced relays, scored a 2J-Racing Ground Kit, moched up a few extra ground straps on my own and car started and runs cherry ever since.

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Also things you are replacing I too had already replaced, cheers and good mood always.
 

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Discussion Starter · #16 ·
The 2 codes were cleared manually before I took ECU out. Put the code reader on today and MIL status was OFF. The codes didn't show but I'm wondering if that's because the car hasn't been driven since they were cleared.
Did a fuel pressure test with key on today and it kind of jumped around. First reading was about 20 then the next two were 35 and 40. Fuel pressure regulator maybe? This was at the rail.
 

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I would recommend against aftermarket grounding kits. They cause more problems than they solve. If there is an existing ground issue, replace the main grounds and it should resolve itself.
When it comes to Nissan, the grounding strap for the negative cable is complete shit. The car does benefit from having additional grounds throughout. Especially on the early models where wiring is a very big problem.

All three of the newer models I had, benefited from additional ground, even if only one or two.
 
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