2003 A4 1.8 T quattro

I am getting error codes P0402 and P0501.

P 0501 is a speed sensor error. My ABS and traction lights come on 1/2 of the time when i start, and when they do come on the speedometer doesnt work at all. i have witnessed speedometer working, hit a bump, then speedometer goes dead and ABS and traction light are lit. but then upon next start everything will work fine. i am trying to clear ym CEL for an inspection and want to focus on this error for now. I ordered an ABS speed sensor, a Crankshaft position sensor or Engine Speed Sensor, and what the parts place called a Vehicle Speed Sensor that i cant find a place for.

The one on the far left is the "Vehicle speed sensor," i have no idea where to look to replace that part.

the center is an ABS sensor. I have vag com but still cant deduce if any of the ABS sensors are bad and if so, which wheel.

the right is the crankshaft position or engine speed sensor, which is right behind the oil filter but wasnt the problem, as when i disconnected the existing one it THEN gave me a crankshaft position sensor-specific error. So im hoping its one of the two on the left giving me 0501.

can anyone shed any light? happy to answer any questions, please help!

thanks

-steve

 

UPDATE: I located a thread showing the Vehicle Speed Sensor pictured far left being on the transaxle. However on my car thats just an empty space and the hole appears to be filled in.

im just wondering what's throwing P0501 if i don't even have this sensor on my car. engine is a replacement but transmission is original.

having pulled the connector for the engine speed sensor and getting a new DIFFERENT code, that goes away when i plug it in, i figured the engine speed sensor (crankshaft position) wasnt the problem, but maybe it still is?

car WILL REV well above 5k

Have read a few places front driver ABS sensor might be bad or else ABS module might need to be rebuilt? is there any way to test any of this?

any help greatly appreciated!

 

It's definitely not your crank sensor. Trust me when I say that if it was, the car may not even start, let alone run and idle. Your crank sensor tells your pcm how fast your crank is rotating and processes that information to tell the coil packs when to spark and is especially the new form of a distributor, it controls vehicle timing. When it's bad. You have a bigger problem. To me it sounds lIke an abs sensor. And judging by how it will go on and off sounds more like there is a lose wire somewhere in the circuit not an actual sensor bad. If like most modern vehicles that sensor should be somewhere near your wheel bearings. Alot of the times it would throw a specific code and tell you which one was bad. But with you getting the generic code it honestly hard to tell without actually having each individual sensor tested. I would start by checking all the wiring too each senor, or even the main ground. Print off a wiring diagram for the abs sensors and go from there. Without a multimeter or a way to look at the waveform the sensors are putting out and the knowledge to understand what the readings are supposed to be it would be hard to single out which one was bad.

 

i have a 2003 audi a4 3.0 quattro the code p0501 is showing for vehicle speed sensor.the sensor on my car is not located on the front differential like most others.where can i find the correct sensor .i read that the front driver side abs sensor is the sensor. my speedometer only works at times for about 5 seconds than shuts off and the trip counter doesnt work.can someone please help me out

 

ok my car is 2004 audi A4 3.0 v6 6 speed. Steve thank you for feedback but you have different motor.