Lexus Is300 Gearbox P0715 And Speed Sensor

n1tr0_9 · February 22, 2015

I recently bought a Lexus is300 sportcross with 114,000 miles. The e-shift function desnt work. This weekend I read the error codes and it keeps coming up with p0715 which is for the gearbox's front speed sensor. Im planning on swapping the sensor and hoping that restores the e-shift, but reading a thread on a US website it says that the sensor might be fine, and that the error is generated by a speed difference between the sensor at the front of the gearbox and the sensor at the rear. The suggestion was that the transmission will need a rebuild.

Every other aspect of the gearbox works fine. Its very smooth, no knocks or bangs and power mode works. Ive flushed the fluid, replaced the internal gearbox filter. There was no major swarf or debris in the fluid and although it was dark, it was not really bad.

My question is, has anyone else had this sensor fail? Is it a common problem? Or is it more likely my tranny is on its way out?

ColinBarber · February 22, 2015

It isn't a common fault of either the IS300 or GS300 which share the same gearbox.

For that error code the issue in order of likelihood is:

the front sensor

wiring

ECU

a problem in the transmission which is causing an abnormal speed difference.

I'd certainly start with the front sensor. I've attached the troubleshooting guide

CIP0715.PDF

n1tr0_9 · February 22, 2015

Excellent, thanks for your help. Ill buy a sensor and try that first.

Where did you find that document by the way? Is it available for the whole car?

ColinBarber · February 22, 2015

you can get online access at Lexus' official site, subscription is time based but only a couple of £ for an hour:

http://www.lexus-tech.eu

in the past you could download the sections you were interested in, now I believe it is all online only.

You should be able to test the sensor rather than having to purchase one - depending on what test equipment you have access to.

n1tr0_9 · February 22, 2015

I can check the resistance and wave a magnet at it, but its having the time to do it. I wish id had that document when the car was up in the air today!

n1tr0_9 · March 8, 2015

I fitted a new sensor and it made no difference. I attempted to check the wiring from ecu to the plug on gearbox but my ecu is different to the one in that PDF above.

I have lpg fitted to my car and I know that having lpg can confuse the fuel gauge. I'm starting to wonder I some how the gearbox also uses info on fuel usage to calculate load or something and maybe that's why it won't use e-shift?

Any ideas?