Need help with transmission
08-18-17, 09:46 PM
#1
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Need help with transmission
i have a 2001 lexus gs300 with 265,xxx miles and I recently got a check engine light with a P0715 code along with other codes. The P0715 code is a input/turbine speed sensor. I took it to a transmission shop and they said that changing the speed sensor won't help. Should I just buy a whole new transmission? It shifts normally but pick up speed really slow and it idles really low under 500 rpms and wants to turn off when I stop at a stoplight. Thanks in advance for the help!
08-20-17, 12:20 PM
#2
typical lazy automotive technicians. especially trans. shops. all alot of them want to do is just sell you a new rebuilt transmission. theres not alot of profit in replacing a speed sensor. the input speed sensor can be diagnosed using a scope to observe the signal its producing. if no signal than likely the sensor is bad. yes your trans has alot of miles on it but i wouldn't be surprised if your trans still has more life left to it. but higher mileage and heat over the years does take its toll on solenoids and sensors. replace input shaft speed sensor and see what happens.
08-21-17, 08:02 AM
#3
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I agree. They evidently don't know Lexus vehicles because the engine and transmissions on these cars are pretty much bulletproof. A speed sensor is a simple replacement (less than $50?) and definitely worth trying.
As for your idle issue, see if you have a vacuum leak. My GS400 would often times idle very low at stoplights and when the engine was warm. Sometimes it would shut off entirely but I could immediately start it back up. The RPMs would remain very low though (like half of what they should be). Took it to the dealer and they said it was a cracked vacuum hose near the purge valve. Very simple fix.
As for your idle issue, see if you have a vacuum leak. My GS400 would often times idle very low at stoplights and when the engine was warm. Sometimes it would shut off entirely but I could immediately start it back up. The RPMs would remain very low though (like half of what they should be). Took it to the dealer and they said it was a cracked vacuum hose near the purge valve. Very simple fix.
Last edited by kevin3344; 08-21-17 at 08:12 AM.
08-21-17, 03:33 PM
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I agree. They evidently don't know Lexus vehicles because the engine and transmissions on these cars are pretty much bulletproof. A speed sensor is a simple replacement (less than $50?) and definitely worth trying.
As for your idle issue, see if you have a vacuum leak. My GS400 would often times idle very low at stoplights and when the engine was warm. Sometimes it would shut off entirely but I could immediately start it back up. The RPMs would remain very low though (like half of what they should be). Took it to the dealer and they said it was a cracked vacuum hose near the purge valve. Very simple fix.
As for your idle issue, see if you have a vacuum leak. My GS400 would often times idle very low at stoplights and when the engine was warm. Sometimes it would shut off entirely but I could immediately start it back up. The RPMs would remain very low though (like half of what they should be). Took it to the dealer and they said it was a cracked vacuum hose near the purge valve. Very simple fix.
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