PCM question. URGENT!!!!

[solarcar_sc1]

thank you for reading. I am currently swapping out a 1999 saturn SC1 (sohc) motor for a 1999 saturn SW2 (dohc) motor, the SW2 had 4 plugs going into the PCM while my SC1 only had 3 plugs, however the sohc pcm has 4 slots for 4 plugs, and Im missing one. I was told that i can use the existing sohc harness with the dohc motor. is this true and if so what was the other plug for?

[solarcar_sc1]

and if I can use the sohc harness, will the vehicle still be able to perform?

thank you.

[OldNuc]

Is the SOHC a manual and the DOHC an automatic?

[solarcar_sc1]

no they are both manual trans. no abs on either. same options

[OldNuc]

I would pull the DOHC engine harness, cluster and PCM and stick them into your modified SC.

PCM connectors.

J-1 Lt Blue 32 pin
J-2 Lt Blue 24 pin
J-3 Pink 32 pin Auto trans cars only
J-3 Brown 32 pin Manual trans cars only
J-4 Pink 24 pin Auto Trans cars

Manual harness/car has 3 connectors, 2 blue and 1 brown.

[fetchitfido]

But the SOHC _WAS_ an automatic right? Before you converted it to manual?
The autotragic computer is built into the same module as the PCM, ABS is a separate module. When I converted a '93 SL2 I had a left over connector and just had to hold the ABS module from attacking my head (don't have to worry about that with 2nd/3rd gens) when I put a '94 SC2 computer in it. I also took the PCM from a '97 SL2 5spd that had ABS, pcm only has 3 connectors and had a separate module for the ABS.

[solarcar_sc1]

The sohc was a manual from the factory. As for the dohc harness. The nimwits at the salvage yard decided on the brilliant idea of cutting the harnes just behind the driver headlight.

[OldNuc]

What are the connector colors on the harness with the 4 connectors and the same for the 3 connector harness.

[madpogue]

It's possible that if you look in the donor car, you'll see four harness connectors under the dash ===> donor car experienced a manual swap sometime in the past and the surgeon retained the auto PCM.

[solarcar_sc1]

The donor harness had 2 brown 2 blue. The sohc has 2 blue and 1 brown which is the large connector missing the small brown connector. Both are 1999. Im truing to get ahold of the salvage guy to see if he can match up vin numbers.

[solarcar_sc1]

But of course they didnt answer

[OldNuc]

Was one of the brown connectors actually pink?

[madpogue]

And the donor PCM has four connectors? And, sorry gotta ask, you def. saw a manual shifter in the donor car?

[solarcar_sc1]

100 percent positive. Its the same car i took the shifter cables out of. Just incase the original fray.