Land Rover Repair: transmission speed sensors, land rover discovery, automatic gearbox

Question
Hi John,
I'm having a problem with my land rover discovery II 2000...automatic trans, V8.  The transmission went out, we didn't have the cash to get a brand new trans, so we got a used one...with low milage...in great condition.  I had a transmission shop put it in....and it works great...besides for a few problems. The check engine soon light was still on, and they didn't have the key to read it. I took it to AutoZone, they read the codes.  PO722, PO741...the first is the output speed sensor, the second is the torque converter.  I think that if we change the sensor, that will fix the code with the torque converter...but at least that's what we are going to try first.  So long long story short, I'm trying to figure out if this is something that we can do ourselves.  I was wondering if you knew where the sensors are located on the transmission.  I have the cd that has all the information about the vehicle...from the dealer...but it's not on there anywhere.  I can't afford to put it back in the shop.  I really need help to find this sensor.  Do you have to drop the trans to get to it? Can you please help? Thanks so much I appreciate whatever you can tell me thanks!!!!

Answer
Hi Nicole,

Did you see P0500 or P0501 codes as well?  I believe VSS is inside the transmission on DII's, harness on the outside (rear area of tranny).  You may be right that the tranny vss is sending problems to the ECU that also affects the TCU.

There are good pictograms of the VSS location within the AUTOMATIC GEARBOX - ZF4HP22 - 24 section :  Valve Body Assembly (pps. 526-527, p.532) of the workshop cd.  VSS is measures output shaft speed and ECU compares that with wheel speed sensors.

Best of luck,

JohnMc