swapped harness from 1.5 to obd2 car wont start help !!

[beretta777]

Ok did the multi meter deal not sure if I was doing it right or not if I had it all set right. But heres how I had it and what I got black probe in the ground, red probe in the +V ohm sign im guessing and the A then the knob set at Rx1k this is the only setting I could get the needle to move. It only moved a little barely off the starting point. This was from the case to the motor. So does this tell me the computer has a ground??

[Rettax3]

Since you are using an analog meter (with the needle instead of digital numbers), set the meter at the lowest number range for Ohms, 1k means 1 thousand, that is not sensitive enough to determine if you have a good ground or not. You are looking for 1, or 2, maybe 4. If you have 1 thousand Ohms of resistance you do NOT have a good ground. With the probes in the air not touching anything at all, the needle should be fully to one side of the meter (without seeing the meter itself, I couldn't say left or right, but it should point at a symbol that looks like a figure-8 on its' side). Touching the probes together, the needle should swing all the way over to the other side, there will be a zero on one of the scales of the meter. The PCM case to the engine should show about the same deflection of the needle away from the sideways figure-8 as when the probes are touching each other directly.

Edit: the Ohm sign looks like a horse-shoe, so if that is on the port you are plugged into on the meter, that is correct.

[beretta777]

So I would wanna put it on Rx1. Ill try this again but I'm wondering could I take a wire or strap bolt it to the case and then to the ground of the battery or car body and this way I know I have a good ground or wouldn't that work?

[beretta777]

Ok so went and got a new meter I set it on the lowest ohms setting which is 200. From the case to the alt. I got 1.4 from the case to the coil pack metal bracket I got 00.6 and from the case to the fuel rail I got 00.4. Does any of this make sense?

[Rettax3]

Yeah, at that low of a resistance, surface-grime, dirt or a less-than perfect contact (even variations in probe-to-surface pressure) can cause that difference. Okay, so it doesn't look like you have a grounding issue. Hey, at least you have a decent meter now to check the rest of the wires.

[3X00-Modified]

Ok... As I stated you need to supply power to the MAF sensor... The ABS wiring I suggested in the write up does two things, It re-routes the wiring for the ABS and provides a power source out to the MAF sensor.

I'm trying to find my old info to verify it because I think I didn't explain it well in the thread... Let me double check to see if this step is critical to starting the car...

Tap pin F4 on the drives side plug in the bay and connect that to the rectangle plug at Pin P on the passenger side by the ECM.

[3X00-Modified]

You need to do this step

Tap pin F4 on the drives side plug in the bay and connect that to the rectangle plug at Pin P on the passenger side by the ECM.

Image of wire you need to splice on to to get power.


Run it through the engine bay harness over to the rectangle plug near the ECM, Cut the Pink wire at PIN P



Then take the wire you ran and connect it to the engine bay side of the wire you just cut, leaving Pin P empty on the square plug since you don't care about the ABS light. The white wire hooked up in this image is the ABS light wire.



I ran a yellow wire in this step so you can follow that in your head.

[beretta777]

Ok but is that really the reason the injectors are not opening.

[3X00-Modified]

You wont know till you try, and I had to change/add that wire to make it work on my 95... so odds are quite high that this is preventing your car from starting. Only two steps of those wiring fixes are optional, the tach and the ABS wire. This one is not optional.

If that is the wire I remember it being, not only does it supply power to the MAF but it supplies power to Pin 19 and 65 on the ECM which is Ignition power IN, so without that the ECM isn't even on. Hence why you can't connect with the scanner either.

[beretta777]

Ok ill give that a shot thanks

[Rettax3]

If that is the wire I remember it being, not only does it supply power to the MAF but it supplies power to Pin 19 and 65 on the ECM which is Ignition power IN, so without that the ECM isn't even on. Hence why you can't connect with the scanner either.

Pins 19 and 65? For the '97 Lumina, I am showing ignition power to be Pins 19 and 63... 19 and 65 show correct for the '96 Beretta, and it is easily possible that these pins are internally connected so either position could work, it is also possible that the PCM from the Lumina was running with only the power in Pin 19, which might work fine indefinitely, or it could cause an overload in the circuitry, PCM failure, and the end of the world!!! Oh, sorry, no, I got carried away... But definitely check the pin-outs for the Lumina PCM, to make certain it is getting the power-supply it needs to operate correctly.

[heavywoody]

Why are we looking at Lumina wiring? Maybe I missed something but he used a 96 L-body harness.

[Rettax3]

Why are we looking at Lumina wiring? Maybe I missed something but he used a 96 L-body harness.

...With a '97 Lumina PCM...

No it didn't work on the 96 ecu but we tried swapping in a 97 Lumina ecu I had laying around and he could gain access and work with that one. Also I did check the fuses.

[heavywoody]

Missed that, sorry.

I know there is a 97 ECM that works with our car, but I can't remember what it was from... I thought it was from a minivan.

[Rettax3]

The '97 Chevy Venture PCM works, at least with a 3400 swap, and should be right on a 3100 if the 3400 injectors are plugged-in, since '96+ uses MAF instead of speed-density alone. So yeah, a min-van/Beretta hybrid, in a manner of speaking, works.