kouki s-14 5-speed swap CEL question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

racepar1 · 11-13-2008, 10:57 AM

I am doing a 5-speed swap on a kouki s-14 and this is the first 5-speed swap I have done on an OBD2 car. I was told that if I don't wire the 4th and 5th gear switches up to the computer that it will throw a CEL. Is this true? If so are there any tricks to the wiring to avoid the CEL? I don't like half assing my work and I wanna make sure it is done 100000% right the first time. Any help would be appreciated, thanks.

devnull · 11-13-2008, 11:27 AM

It won't throw a CEL for 4th/5th gear switches.

It *will* throw a CEL for the neutral switch.

The computer will look for the neutral switch to close and open at least once each driving cycle. A driving cycle means the time between engine on and engine off.

When I first did my swap my harness had an open circuit to the neutral switch, so I wired up a toggle switch on that circuit and I just switch it on and off when I get going.

Also, since this is your first OBD2, remember that you must remove the crankshaft position sensor before removing or installing the transmission. If you leave it in it is likely you will break it.

racepar1 · 11-13-2008, 11:41 AM

Quote:

Originally Posted by devnull

It won't throw a CEL for 4th/5th gear switches.

It *will* throw a CEL for the neutral switch.

The computer will look for the neutral switch to close and open at least once each driving cycle. A driving cycle means the time between engine on and engine off.

When I first did my swap my harness had an open circuit to the neutral switch, so I wired up a toggle switch on that circuit and I just switch it on and off when I get going.

Also, since this is your first OBD2, remember that you must remove the crankshaft position sensor before removing or installing the transmission. If you leave it in it is likely you will break it.

I pulled the trans with the sensor in, no problems. When installing the 5-speed though I will have the sensor out as clearence is much tighter with the 5-speed. I didn't think that the 4th and 5th gear switches would throw a light, that is cruise control stuff.

projectRDM · 11-13-2008, 12:10 PM

Quote:

Originally Posted by racepar1

I pulled the trans with the sensor in, no problems. When installing the 5-speed though I will have the sensor out as clearence is much tighter with the 5-speed. I didn't think that the 4th and 5th gear switches would throw a light, that is cruise control stuff.

There is no 4th gear switch on S14s, only on the DOHC S13s. The 5th gear switch is mainly used for the speed limiter, not cruise. The cruise can't be set above 90MPH, no matter what gear you're in.
You'll need to use a manual ECU as well otherwise the CEL will trip from missing automatic transmission inputs.

Bigsyke · 11-13-2008, 06:07 PM

True story about the ECU, racepar how was doing the 5speed swap? im about to do mine soon in the spring

racepar1 · 11-13-2008, 08:15 PM

Quote:

Originally Posted by Bigsyke

True story about the ECU, racepar how was doing the 5speed swap? im about to do mine soon in the spring

If you have a kouki, make SURE you have a kouki trans. If you dont you won't be able to put the crank sensor back and it will throw a CEL (duh). I HATE half-assing shit, but my customer didn't quite do all the right research and get the 100% right parts. I was too pre-occupied to do it for him.

Bigsyke · 11-13-2008, 09:18 PM

how long did it take you to complete the swap?

racepar1 · 11-13-2008, 10:56 PM

Quote:

Originally Posted by Bigsyke

how long did it take you to complete the swap?

I'm lagging a bit and missing parts so that is not really a valid question. IF I had all the parts and the free time/motivation it can be done in a day easy.

mxexux · 11-13-2008, 11:15 PM

Hey I have a '97 Manual ECU if you need one. I'm located in Socal. PM me if you are interested.

projectRDM · 11-14-2008, 09:08 AM

Quote:

Originally Posted by racepar1

If you have a kouki, make SURE you have a kouki trans. If you dont you won't be able to put the crank sensor back and it will throw a CEL (duh). I HATE half-assing shit, but my customer didn't quite do all the right research and get the 100% right parts. I was too pre-occupied to do it for him.

Close, make sure you have an S14 transmission. They all have the CPS, 95-98.

racepar1 · 11-15-2008, 05:39 PM

Quote:

Originally Posted by projectRDM

Close, make sure you have an S14 transmission. They all have the CPS, 95-98.

I suspected that it was an 89-90 trans and this verifies my suspicion. Guess who sold the trans as an s-14 trans.... Otis with RBperformance, now known as Otis performance. BIG surprise huh?

projectRDM · 11-15-2008, 11:21 PM

Quote:

Originally Posted by racepar1

I suspected that it was an 89-90 trans and this verifies my suspicion. Guess who sold the trans as an s-14 trans.... Otis with RBperformance, now known as Otis performance. BIG surprise huh?

SOHC transmissions won't have the 4th gear switch, so if it's only got three switches, VSS, and no CPS, it's a 89-90 unit.

racepar1 · 11-16-2008, 12:59 PM

Quote:

Originally Posted by projectRDM

SOHC transmissions won't have the 4th gear switch, so if it's only got three switches, VSS, and no CPS, it's a 89-90 unit.

That's what I thought, it is an 89-90 trans.

11-13-2008, 10:57 AM	#1
racepar1 Post Whore! Join Date: Jul 2007 Location: Simi Valley, CA Age: 38 Posts: 9,006 Trader Rating: (106) Rides Gallery: racepar1 Feedback Score: 106 reviews	kouki s-14 5-speed swap CEL question I am doing a 5-speed swap on a kouki s-14 and this is the first 5-speed swap I have done on an OBD2 car. I was told that if I don't wire the 4th and 5th gear switches up to the computer that it will throw a CEL. Is this true? If so are there any tricks to the wiring to avoid the CEL? I don't like half assing my work and I wanna make sure it is done 100000% right the first time. Any help would be appreciated, thanks.

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11-13-2008, 11:27 AM	#2
devnull Zilvia Member Join Date: Aug 2006 Location: Earth Posts: 222 Trader Rating: (0) Feedback Score: 0 reviews	It won't throw a CEL for 4th/5th gear switches. It will throw a CEL for the neutral switch. The computer will look for the neutral switch to close and open at least once each driving cycle. A driving cycle means the time between engine on and engine off. When I first did my swap my harness had an open circuit to the neutral switch, so I wired up a toggle switch on that circuit and I just switch it on and off when I get going. Also, since this is your first OBD2, remember that you must remove the crankshaft position sensor before removing or installing the transmission. If you leave it in it is likely you will break it.

11-13-2008, 06:07 PM	#5
Bigsyke Zilvia FREAK! Join Date: Jun 2008 Location: NA Age: 36 Posts: 1,342 Trader Rating: (0) Feedback Score: 0 reviews	True story about the ECU, racepar how was doing the 5speed swap? im about to do mine soon in the spring

11-13-2008, 09:18 PM	#7
Bigsyke Zilvia FREAK! Join Date: Jun 2008 Location: NA Age: 36 Posts: 1,342 Trader Rating: (0) Feedback Score: 0 reviews	how long did it take you to complete the swap?

11-13-2008, 11:15 PM	#9
mxexux Zilvia Junkie Join Date: Jun 2008 Location: SoCal 949 Posts: 363 Trader Rating: (9) Feedback Score: 9 reviews	Hey I have a '97 Manual ECU if you need one. I'm located in Socal. PM me if you are interested.