# Check engine light code P0720 (output speed sensor circuit) advice please



## jwill911 (Jul 7, 2016)

My 2009 Jetta just started getting check engine light, it decodes as P0720 (output speed sensor circuit). From some research it is a automatic transmission speed sensor. I don't know where to find the sensor. I have cleared the check engine light twice but it comes back pretty quickly.
It would be great if someone could give me some ideas on where to find it. I'm pretty competent mechanically but don't have a manual. Maybe i should get one but haven't needed one until now.
Any ideas other than taking it in for service. Maybe to an independent transmission shop?
Thanks in advance for any advice.
John
Alameda, CA


----------



## Newparts.com (Jul 12, 2017)

If you have the 09G transmission both the G182 input speed and G195 output speed sensors are located inside the transmission above the valve body. The valve body will need to be removed to access them. Before you go too crazy digging into the transmission, check the wires going to the 8 pin connector just above the transmission oil pan. It is fairly common for the wires to break where they go into the connector. Give them a slight tug to see if the wire is severed inside the insulation. If you have a VW compatible scan tool you can check the measuring value blocks in group 001 which contains the RPM values for the engine, input, and output speed sensors.


----------



## GermanWill (May 25, 2020)

jwill911 said:


> My 2009 Jetta just started getting check engine light, it decodes as P0720 (output speed sensor circuit). From some research it is a automatic transmission speed sensor. I don't know where to find the sensor. I have cleared the check engine light twice but it comes back pretty quickly.
> It would be great if someone could give me some ideas on where to find it. I'm pretty competent mechanically but don't have a manual. Maybe i should get one but haven't needed one until now.
> Any ideas other than taking it in for service. Maybe to an independent transmission shop?
> Thanks in advance for any advice.
> ...


My 2009 came up with this code. The ABS lights and brake light began flashing too. I read about replacing the sensor, and checking the wires at the connector for breaks, but all seemed okay. The car had been sitting for a while and it wasn't a problem before. I hooked up a scanner that showed Group 1 and I could see the sensors working. I also had a function on there that activated the ABS pump. After I activated the ABS pump with the scanner, the code went away, the ABS lights went off. I'm thinking the ABS pump had just been stuck, after sitting for a year. Perhaps this somehow made the sensors seem to register wrong.


----------

