P1899 code on TJ with 30RH swapped to NSG370

Choptop1954

Choptop1954

New Member
Joined
Jul 28, 2020
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15
Location
Concord CA
Soooooo just bought this Jeep it’s a 2001 Sarah that apparently came factory with a 3 speed but the previous owner said he got the guys at Jeep speed to install a 6 speed with and atlas 2. Everything works great but I get an engine code P1899 (park/neutral switch circuit conditions). I need to smog it but can’t because of this. Is there anyway to bypass or close the circuit so this check engine light will go away?

Thank you for your time.
-Dru
 
Choptop1954 said:
Soooooo just bought this Jeep it’s a 2001 Sarah that apparently came factory with a 3 speed but the previous owner said he got the guys at Jeep speed to install a 6 speed with and atlas 2. Everything works great but I get an engine code P1899 (park/neutral switch circuit conditions). I need to smog it but can’t because of this. Is there anyway to bypass or close the circuit so this check engine light will go away?

Thank you for your time.
-Dru
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There are a few codes I can believe it would throw, that isn't on the list. They must not have hooked up the neutral safety switch and bypassed it some how. How are they doing the crank position sensor? Get a pic of the harmonic balancer from underneath and post it up.
 
mrblaine said:
There are a few codes I can believe it would throw, that isn't on the list. They must not have hooked up the neutral safety switch and bypassed it some how. How are they doing the crank position sensor? Get a pic of the harmonic balancer from underneath and post it up.
Click to expand...

CBABA23E-5CC9-447B-8FDC-26D2693C14B4.jpeg


350F6728-D1C5-4CB6-9934-7E9AD897B7CB.jpeg
 
Choptop1954 said:
I do no t know where the cps is. I thought it be on the motor by the oil filter maybe? But I’m not sure where to look.
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Do you know if they changed the PCM to the one for the manual transmission? If you aren't sure, post up a pic of the part number on the PCM.
 
Choptop1954 said:
Soooooo just bought this Jeep it’s a 2001 Sarah that apparently came factory with a 3 speed but the previous owner said he got the guys at Jeep speed to install a 6 speed with and atlas 2. Everything works great but I get an engine code P1899 (park/neutral switch circuit conditions). I need to smog it but can’t because of this. Is there anyway to bypass or close the circuit so this check engine light will go away?

Thank you for your time.
-Dru
Click to expand...
The answer to your question is yes, it can be bypassed and put on a switch or hooked up correctly. The problem is they likely just grounded it out to allow the engine to start rather than hook it up correctly to the clutch safety switch.

We need to know the PCM you have, whether you can start it with the clutch out, and if the CPS is still over the starter.
 
Choptop1954 said:
Does this help?

View attachment 180390
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Yes, that helps, that is the original part number for the 4.0 with the 32RH auto. You should have 2 CELs tripped. As soon as you power that PCM up without the transmission torque converter lock up connector plugged in, it will trip a code for a faulty circuit at a minimum.

So, what we think is happening is they put a resistor or something on the the TCC to stop that code if you are pretty sure it isn't showing up.

What they probably did to get it to start is they grounded the NSS circuit so it will start all the time (which you still haven't told us is the case yet) instead of making the clutch safety switch circuit work. If they did that, then as soon as the speed sensor tells the PCM that the vehicle is moving, it trips a code due to the circuit being grounded.
 
Choptop1954 said:
Here’s this too

View attachment 180404
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Now we're gonna have to get some smarter folks involved. Everything we know says the engine shouldn't run or run well with the CPS on that side. The reason the CPS is there instead of over on the other side is they changed the firing rotation on the crank in 05 to be every 180 degrees instead of the older 120 degrees.

Look under the rig above the trans for an empty connector with something stuck in it.
 
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We are working on the jeep at my house and it will start without depressing the clutch and I checked over the transmission and found a harness with what looks like a relay in one of the connectors
90BFCC37-FC9A-4A68-AD9D-A286951E6DC4.jpeg
 
Hey I’m getting ready to give up on figuring out this problem at home, does anyone know a good Jeep shop that could handle this problem? I’m located in the Bay Area but willing to travel.
 
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