Maltrix

TLDR: Shifter won't let me reverse once its been placed in drive, have to shut off car to reach reverse. I dont want to throw parts at it so was wondering if this is indeed a PNP switch malfunction or might possibly be something else.

So one of the OCV went on my 99 with 280k on it. It sat for a week waiting for part to come in. After I installed it i fired her up to listen how she was running. The dash lights came on slowly and I noticed that R N D were lit up, my girlfriend drives this car much more than I do so I couldnt recall if that was normal or not but it started up fine so I brushed it off. After a few minutes i shut her down so I could fit the air fliter back on and when I went to fire her up again the lights were dim and she started to sputter. I had suspicions of her having a bad battery from a few months ago when she needed a jump after a cold morning but the tests shown she was fine and she never died out again till now. So I swapped a good battery into her and she started up fine, backing up I noticed a CEL came on.

I put her into drive for a moment and when I went to put her back into reverse the shifter wouldn't move, I could hear some noise and buzzing coming from under the shifter and after some playing around with it it let me get back into reverse. The CEL is p1780, PNP switch malfunction. I drove her around for awhile and it seems once she's in drive she can only go up to neutral and no farther, I have to shut her off and put her in park to get to reverse. The D light stays on now while shes in park. It seems this problem isn't super common so I wanted to ask what you guys think before I go ahead and buy parts. The noise I was hearing under the shifter has me second guessing replacing the PNP switch. Any thoughts on this topic would be very helpful thanks.

Yamae

I think the switch is internally short circuited or the wiring harness to it is short circuited. You can distinguish it removing the connector from the switch located at the side of the AT.

Maltrix

How do i test it once it's disconnected? Will I be able to operate the AT without it?

Yamae

All you have to do is to turn the ignition key to "ON"/"RUN" position after disconnecting the connector. There's no need to worry about the AT since the engine doesn't start. Seeing the AT indicator, you will know that it's a problem of the switch or the harness.