VSS......and TCC?

Hello, I have a 1986 Oldsmobile Delta88 3.8L V6. This winter i started getting the "Service engine soon" light. I took it to be fixed and they retrieved a TPS code. The sensor was replaced and adjusted.

But now i am getting another "Service engine soon" light with a code

24, which is a Vehicle Speed Sensor (VSS) code. The light comes on the first time i run the car in the morning, when the wheels are not moving (parked). And when i start moving the service engine soon light turns off. It does not come back for the rest of the day. The car also has a high idle.

The car starts to do a surge condition when i start to brake for a red light.

Recently i had a leak from the power steering lines that run over the transmission. Could this have caused this problem? Maybe got on the VSS or TCC contacts.

Any of you guys ever have this problem? What you think it might be?

I already spend much this winter.

Reply to
myc1972
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24 is the Speed Sensor Circuit problem code. It's not just about the VSS, it concerns the whole electrical speed sensor circuit. You had the TPS replaced and now there is a throttle problem. Possibly the TPS is adjusted correctly and/or the ISC throttle switch is Open. Do you know if the code is stored as a Hard code or an Intermittent one? Prior to the first problem, was the speedometer working correctly?

This electrical problem has little/nothing to do with the transmission converter clutch(TCC).

Dave S(Texas)

Reply to
putt

I am reading through the diagnostic aids and it says "disregard code 24 that sets when drive wheels are not turning." Do you have any other codes coming up?

It also says "a faulty or misadjusted park/neutral switch can result in a false code 24." I would start by diagnosing that.

Steve

Reply to
Steve Mackie

The Code 24 gets stored in the computer, it does not get erased unless i disconnect the battery. Would that make it a Hard code? As far as i could tell the speedometer has been working correctly always.

When the car starts to surge when i apply the brakes there is no Service engine soon light that comes on.

I also read that if that code 24 is set when the drive wheels are not moving to disregard it. but i am still getting the surging and high idle, so there is a problem somewhere.

Thank you for replying so fast guys, i really appreciate it, i need all the help i can get.

Reply to
myc1972

Yes, and I'm saying it is in the TPS/ISC units. Take the vehicle back to the garage that installed the TPS and relate the problem. I believe the ISC wasn't serviced correctly when the TPS was installed. The ISC is in Open position when it should be in Closed position.

Dave S(Texas)

Reply to
putt

what is the ISC?

Thanks!

Reply to
myc1972

ISC = Idle Speed Controller It adjusts for a steady idle speed by compensating for engine load via input from the TPS (Throttle Position Sensor). The ISC can get carboned-up internally; some have cleaned them, but replacement is recommended.

Reply to
Sharon K.Cooke

Thanks....is that your name??

Anyway, the ISC is short for Idle Speed Control. It is a small electro-mechanical unit that lives near the TB. The ECM senses variations in voltage from the TPS and uses those signal the ISC. If the ISC wasn't properly set after the new TPS was installed, the problem you describe is the result. BTW: disconnecting the power to the ECM is not a good way to clear the codes. Doing that clears all the driving history that has been built-up....this is the RAM in the computer. Losing the RAM makes the ECM revert to using the ROM. The ROM is the inbedded memory from when every system/sensor on the vehicle was brand-new. The RAM is the compensation (program) for the ROM. The vehicle won't run very well while it's using only the ROM. Eventually a RAM will be rebuilt with driving, but it takes time. Most good scan tools have a feature to 'clear' the codes, without also 'clearing' the RAM.

Dave S(Texas)

Reply to
putt

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