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1996 Grand Prix se 4dr

unclesonny

New member
Hello all,

Having an issue with transmission I think... This started last week and wondering if someone may have a few thoughts on what is happening..
When I get going in the morning, trans shifts great. I can give it a bit and there is no slippage.. After 30mins. approx. it starts to slip after coming off a light etc. On the highway at faster speeds, 60-70 not a problem.
Speedo lags behind in what speed my car is actually traveling, only at the slower city speeds.. Fluctuates around in the early gear shifts than seems to correct itself at higher speeds, above 60-80kph.
I pulled the VSS out to inspect and found the tip clogged up a bit and the inside base of the sensor with what looked like a grey in colour anti-seize compound, rather thick around inside of sensor base, plus what looks like metal filings from perhaps clutch material??
Have a scanner which gave me a code of P0502, indicating a CKT low input from sensor.
This was last night.. Used the car this morning and check engine light was still on, with that code...
Started car to put it up to remove sensor and check engine light was off.

My understanding, as to the correct procedure to test this sensor is to run the car with wheels turning and to look for a changing resistance. Also, the ohms reading should be approx. 190-250 ohms. I have a reading of 1.3k with it out....
Could someone confirm the above specs and the procedure.

Cleaned up the sensor and will re-install to see if this may be the fault.
I'm including some of the info from scanner,
VEH SPEED (MPH) = 14
TCC PWM = 98.0
TCC SLIP (RPM) = 7915
TOT (V) = 3.078
TOT (F) = 147.2
TRANS OSS (RPM) = 573
GEAR CURRENT = 2

The TCC SLIP (RPM) changes from almost 1 to 8000 rpm, but trans at the higher speeds seems to shift fine...

Any thoughts will be appreciated...
 


Hello all,

Having an issue with transmission I think... This started last week and wondering if someone may have a few thoughts on what is happening..
When I get going in the morning, trans shifts great. I can give it a bit and there is no slippage.. After 30mins. approx. it starts to slip after coming off a light etc. On the highway at faster speeds, 60-70 not a problem.
Speedo lags behind in what speed my car is actually traveling, only at the slower city speeds.. Fluctuates around in the early gear shifts than seems to correct itself at higher speeds, above 60-80kph.
I pulled the VSS out to inspect and found the tip clogged up a bit and the inside base of the sensor with what looked like a grey in colour anti-seize compound, rather thick around inside of sensor base, plus what looks like metal filings from perhaps clutch material??
Have a scanner which gave me a code of P0502, indicating a CKT low input from sensor.
This was last night.. Used the car this morning and check engine light was still on, with that code...
Started car to put it up to remove sensor and check engine light was off.

My understanding, as to the correct procedure to test this sensor is to run the car with wheels turning and to look for a changing resistance. Also, the ohms reading should be approx. 190-250 ohms. I have a reading of 1.3k with it out....
Could someone confirm the above specs and the procedure.

Cleaned up the sensor and will re-install to see if this may be the fault.
I'm including some of the info from scanner,
VEH SPEED (MPH) = 14
TCC PWM = 98.0
TCC SLIP (RPM) = 7915
TOT (V) = 3.078
TOT (F) = 147.2
TRANS OSS (RPM) = 573
GEAR CURRENT = 2

The TCC SLIP (RPM) changes from almost 1 to 8000 rpm, but trans at the higher speeds seems to shift fine...

Any thoughts will be appreciated...

Update


Fixed trans problem. Found yellow wire coming from VSS to have a break inside insulation about a inch from connector. Could not see this before. Ohm reading from pin 6 yellow wire and pin 47 purple wire at ecm confirmed bad yellow wire.
Hope this may help someone else.
 
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