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Please help...error codes P0135 & P0502 and problems with tranny

4.5K views 8 replies 3 participants last post by  ajm786  
#1 ·
The car is a 1999 Oldsmobile 88 LS. It has 64K miles on the engine.

The problem that I'm having is doublefold.

1. Randomly, when I shift into reverse, the car will not respond. If I give it a little gas, it will begin to reverse, slowly. Sometimes, it will not reverse at all. Other times, it works perfectly.
2. I was sitting at a traffic stop with the car. As the traffic started to move, I slightly touched the gas, and the car started vibrating/shuddering extremely VIOLENTLY, for about 2 seconds, then started driving normally. I first I thought I went over some rocks. But then it did it again, and again.

Doing some research on the net, I found GM TSB 00-07-30-002B which says that it's the pressure control solenoid. So I took it to a shop to do some diagnostics. They hooked up their scanner, and got the following error codes:

P0502 VSS Circuit Low Input
P0135 H02S Heater Circuit Bank 1 Sensor 1

The mechanic at the shop mentioned that he's seen cars with the VSS go bad do all sorts of things, including the problem I explained.

Now here's the question. I'm really scared because if it is the solenoid problem, it's going to cost a lot to get it replaced, since the entire transmission needs to be dropped to get access to it. But, on the flip side, isn't it true that if the solenoids go bad, it wouldn't necessarily throw a check engine light (which it is not in this case), but would at least throw a DTC error code? Also, I'm skeptical that it's the VSS, because if it was, wouldn't my dash gauges be doing funny things (which it is NOT)?

I'm totally lost/confused as to what the cause of this problem is. I'd like some feedback and some help/suggestions to get me on my way.

Thanks in advance!!!
 
#2 ·
If the vehicle speed sensor is failing you can get the symptoms described.
The most cost effective thing for you to do is change the easy, inexpensive vss and see if it clears up. Was your speedometer doing weird stuff recently?
 
#3 · (Edited)
Was your speedometer doing weird stuff recently?
No, it did not exhibit any issues with the speedometer.

Also, I was thinking it may not be the transmission at all. I took the car on an old backroad where there is little to no traffic, and FLOORED the throttle. The car never exhibited any problems when doing this.

It only does it randomly at mostly traffic light stops, where traffic is touch and go.
 
#4 ·
A few guys have found that the pcs can be helped by tossing in a shift kit, one bottle of Lucas stop slip and a trans service. Something about the fast shift seems to clear up the pcs issue. It's probably more of a bandaid, but if it works who is complaining.
 
#6 ·
Most are using the Intense-Racing shift kit from their site. And yes, drop the pan to do the kit and replace the filter and refill with fluid. I frequently try to slim it down by saying service.
 
#8 ·
I added the Lucas transmission fix and it did not help/fix the problem. I am receiving the new VSS and thermostat today. I will install those and report back.

I still need suggestions/help if anyone can provide. Reason is that I am still leery of taking it to the dealership; how do I know they are not going to diagnose the problem properly and just try to maximize profits at my expense? I don't have an unlimited budget for this.
 
#9 ·
I installed the new VSS and put the Lucas transmission fix in and it did not fix the problem. Although the car does run much smoother now.

Also, I am able to properly replicate the problem. Here's the procedure.

1. Drive the car to bring it up to normal operating temperature.
2. Turn the car off. Doesn't matter if it's momentary, just turn it off.
3. Drive the car again. If I come to a complete stop, then start accelerating slightly, the moment I touch the accelerator the car will vibrate/shudder/shake violently till I take my foot off the accelerator. When I do, the shaking stops completely, and the car accelerates properly again.

I'm thinking now more than ever that it is indeed the PCS solenoid.