Bad Engine Harness????

[240silvia]

Possible engine harness being bad?????

I checked the codes on the ECU. With the ignition OFF I got 11, 12, 14, 21.

Which is...

11 - Camshaft position sensor

12 - Mass Air Flow Meter Sensor

14 - Vehicle Speed Sensor signal circuit is open (speedo isn't working while driving)

21 - Ignition signal in the primary circuit is not being entered to the ECU during cranking or tuning

With th eignition ON I got a 55, which is no problems. That is weird to me.

Any ideas?

[projectRDM]

There should be no codes with the key off as the ECU is NOT powered. if it is, you have a wiring problem.

[240silvia]

DOHC, auto to manual swap. No EGR and Apexi N1 are the only mods

[240silvia]

and I made a mistake in the first post. The power was on, i took the first reading, then I started the car which erased the codes. Which is why I got a 55 the second time. So, don't pay attention to the first post.

The maf is off a working car. And the distributor is also.

[chrisdot]

i dont know if it applies to u or not but i just did an auto to 5 speed swap on my s14 but i also put an sr in it... by the fuse box there is a bunch of shit that is needed for auto that isnt needed for manual and there is one thing that u need to run a jumper wire for right, its connected to the fuse box but im outta town and cant get u pics til next week, if u still have the problem i will send u pix. look at someone car that is manual and compare it to ur fuse box

[projectRDM]

i dont know if it applies to u or not but i just did an auto to 5 speed swap on my s14 but i also put an sr in it... by the fuse box there is a bunch of shit that is needed for auto that isnt needed for manual and there is one thing that u need to run a jumper wire for right, its connected to the fuse box but im outta town and cant get u pics til next week, if u still have the problem i will send u pix. look at someone car that is manual and compare it to ur fuse box

Car wouldn't start without that. We know this.

OP- Are there any codes now, after driving it?

[240silvia]

I actually haven't drove it since. I'm actually scared to because of the spark knock. I have a spare engine harness laying around so I think I might try and swap them out, just to see what happens.

I ran a continuity test on the plug that plugs into the distributor, and it toned out. But I guess that doesn't mean it doesn't have a short somewhere.

I ment to add, a few days ago the EGI Relay would Buzz when I cut the ignition to the ON position, and then cut it off. If I cranked the car, and then cut it off, it wouldn't do it. The EGI relay has 4 wires on it, 1 ground, 2 constant powers, and 1 switch. The switch wire should only get power when the key is in the ON position. It does, and then when I would but the key off, it would buzz and go down to 8.5 volts. Which leads me to believe something is back feeding through the system.

When it was buzzing, I could unplug the maf plug, and it would change the tone of the buzzing. Same result in the distributor plug. So, I'm changing the harness!!!!

[cotbu]

Did you pickup tone on any of the other wires in the harness, when you tested the distributor? If swapping the harnesses fixes the problem, are you going to repair the your current harness?

[240silvia]

swapped the harness. Same problem. But, Check engine light is coming on when the car is at idle. When I rev the car, it goes off. Code on the ECU is a 21, which is primary ignition signal. Nissan FSM says it's either the Power Transistor, The resistor, or the harness/ connector. I have swapped the power transistor. Which is the black box that's screwed on to the side of the coil. I have not done the resistor which is the smaller black box that's taped to the harness. I have swapped the engine harness so the car has seen two resistors, three power transistors, and 2 connectors. This weekend I'm going to check the wires per the manual. Any ideas anyone?

[Saviorsoul]

swapped the harness. Same problem. But, Check engine light is coming on when the car is at idle. When I rev the car, it goes off. Code on the ECU is a 21, which is primary ignition signal. Nissan FSM says it's either the Power Transistor, The resistor, or the harness/ connector. I have swapped the power transistor. Which is the black box that's screwed on to the side of the coil. I have not done the resistor which is the smaller black box that's taped to the harness. I have swapped the engine harness so the car has seen two resistors, three power transistors, and 2 connectors. This weekend I'm going to check the wires per the manual. Any ideas anyone?

Ever try replacing the relay? I had the same problem with mine buzzing, and then it went away permantly. An now 2 weeks later my car died and it won't start. None of my electronics even turn on when my cars in the ON position aka:radio, fuel pump, auto belts, etc.. I'm gonna try replacing the relay.