Cannot find where the park-neutral switch is located

GORDON61

MEMBER
1999 SATURN SL1
1.8L
4 CYL
2WD
AUTOMATIC
164,000 MILES

Starter and solenoid are brand new. Found out that there is no trigger voltage to activate the solenoid. With the ignition switch on, I hooked a jumper from battery positive to the solenoid terminal to activate the solenoid. The car started up. I have checked the connection pins where the connector plugs into the back of the fuse box located inside the vehicle. No connector pins are burnt and no plastic melted; although I am not sure yet which pin it is. This model Saturn has no starter relay. So seems that only three things remain. Ignition switch, wiring, or park-neutral switch. My problem is that I cannot find a decent schematic and cannot find where the park-neutral switch is located and a easy way to test it without taking a million things apart.

5 Replies

JACOBANDNICKOLAS

MECHANIC
109,724 POSTS

Hi and thanks for using 2CarPros.

I am looking on a schematic and it shows a starter relay. I have attached a schematic of the entire starting system for you to review. I had to break it into two pics because of size. I overlapped the schematic at the relay so you can easily follow it.

Next, the neutral safety switch is located on the right rear section of the trans-axle. It is indicated on the schematic. Pictures 3 and 4 are ignition switch component locations. It is vague, but you can see approximately where the switch is located.

To check the switch, follow these directions:

_______________________

Verify switch integrity

The neutral start switch is OPEN when the trans-axle shifter is in R (reverse), D (drive), 3 (third gear), or 2 (second gear). When the trans-axle selector is in P (park) or N (neutral) the switch closes allowing current to flow from the ignition switch to the starter solenoid. Current flows from the ignition switch, through the UHJB to the neutral start switch on circuit 6A (purple wire), through the switch to circuit 6X and on to the starter solenoid. Verify switch by back probing both terminals A and B at the Neutral Start Switch with shifter in Park and ignition in the "crank" position with a DVOM to ground. If no voltage is present at terminal A, inspect circuit 6A and 5A for poor connections or opens, starter relay, 30A ION 3 fuse (UHJB) and ignition switch.

________________________________

Let me know if any of this helps.

Take care,
Joe

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Tuesday, April 20th, 2021 AT 11:18 AM

GORDON61

MEMBER
3 POSTS

Finally had time to get back to look more at this problem. I found the starter relay. I tested the relay on my work bench and it works fine. When I probe the relay socket in the car, I find that I am getting 12 volts to one side of the coil and also 12 volts to the common on the contact. However, the relay will not activate. When I placed a jumper across the starter relay contact and tried the ignition the car started. So I now know that the ignition switch and NSS switch are good. When I hook my meter across the coil of the relay I find that I am not getting a ground (negative) to the socket pin for the relay coil. So according to the diagram you gave me, It appears to be either the RKE module or the Left Body Ground Splice Pack. I do not see any ground splice pack under the left front seat.
I need a clear picture of where the RKE module is located. Thanks in advance.

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Tuesday, April 20th, 2021 AT 11:18 AM

JACOBANDNICKOLAS

MECHANIC
109,724 POSTS

Read through this diagnostic test. Let me know what you find. Also, I found a factory schematic that shows the ground. Please keep in mind, if your vehicle has the RKE option, the RKE is what allows the ground to happen. Take a look through this:

1. Verify relay integrity
- The starter relay works in conjunction with RKE system to disable the Starter motor until the RKE module acknowledges the "Unlock" transmission from the FOB. Vehicle built without the RKE option enable the starter relay by shorting circuit 625 to ground.
- Verify relay enable circuitry by back probing both A1 and C2 terminals at the starter relay with doors unlocked by the RKE system and ignition in the Run position with a DVOM to ground. If voltage is present at terminal A1, inspect circuits 625 and 625A for poor connections or opens or RKE module. If no voltage is present at C2, inspect circuit 5A and 5 for poor connections or opens, 30A IGN 3 fuse (UHJB) and ignition switch.
- Verify relay enable circuitry by back probing both A2 and C1 terminals at the starter relay with doors unlocked by the RKE system and ignition in the "Start" position with a DVOM to ground. If no voltage is present at terminal A2, inspect circuits 5A and 5 for poor connections or opens, 30A IGN 3 fuse (UHJB) and ignition switch.

__________________________________

Here is an OEM picture of the ground location. Let me know if this helps.

Joe

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Tuesday, April 20th, 2021 AT 11:18 AM

GORDON61

MEMBER
3 POSTS

Hi Joe. Sorry that I have not responded in a while. I hurt my back while trying to work on this vehicle and have just now got to the point of being able to get back to troubleshooting. I will take a look at the info you sent and see what I find.

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Tuesday, April 20th, 2021 AT 11:18 AM

JACOBANDNICKOLAS

MECHANIC
109,724 POSTS

Welcome back:

That's no problem at all. Sorry to hear you hurt yourself. Let me know what you find or if you have questions. If I don't hear from you for awhile, I wish you and your family a great Christmas.

Take care of the back!

Joe