help identify this sensor on A4 quattro 3.0L engine

**audi-owner** · 09-20-2016 07:18 AM

I have an 2002 audi a4 Quattro with a 3.0L engine.

I have been researching error code P0392.

I have been able to identify the location of the 4 cam positions sensors - 2 each located on the left & right side of the engine closest to the firewall.

While searching for the location of these sensors, I also noticed an additional sensor that I cannot identify so would like some help.

On the 3.0L, there is a plastic access cover over the intake/exhaust cam timing belt pulley on each side of the engine.

The sensor that I am trying to identify is located on the back side of the timing belt access zone and
appears to be monitoring the back side of the exhaust camshaft pulley.

Each sensor's electrical connection is coming from the coil pack wiring harness on it's respective side of the engine.

does anyone know what this sensor is?..... thanks...

**SJorge3442** · 09-20-2016 09:43 AM

Take a picture of the sensor in question. In the front of the head is the VVT actuator I believe.

**audi-owner** · 09-20-2016 02:00 PM

the first picture shows the camshaft timing belt access cover on the passenger side of the vehicle:
http://jpegbay.com/gallery/005581754-.html#1

the second picture is a side view of the timing pulley access and shows the sensor on the left side of the picture (the wiring harness is connected to it):
http://jpegbay.com/gallery/005581754-.html#2

are these pictures clear enough?

**SJorge3442** · 09-20-2016 06:36 PM

Originally Posted by audi-owner

the first picture shows the camshaft timing belt access cover on the passenger side of the vehicle:
http://jpegbay.com/gallery/005581754-.html#1

the second picture is a side view of the timing pulley access and shows the sensor on the left side of the picture (the wiring harness is connected to it):
http://jpegbay.com/gallery/005581754-.html#2

are these pictures clear enough?

Ah! The sensor at the front of the head that connects to the coil pack harness. Sorry, but I have no idea what that is. Hopefully someone who has ETKA or another Audi part look up diagram can chime in!

**imnuts** · 09-20-2016 06:49 PM

After a little searching, it looks like it may be a cam position sensor.

**SJorge3442** · 09-20-2016 07:43 PM

Originally Posted by imnuts

After a little searching, it looks like it may be a cam position sensor.

I know it shares the same sensor connector, I just wasnt sure if it was the exact same as the ones in the back of the head.

**diagnosticator** · 09-20-2016 08:53 PM

Originally Posted by imnuts

After a little searching, it looks like it may be a cam position sensor.

You are correct.

"I have been able to identify the location of the 4 cam positions sensors - 2 each located on the left & right side of the engine closest to the firewall."

Those are the cam timing actuators that rotate the cams for VVT.

**audi-owner** · 09-20-2016 10:16 PM

Originally Posted by diagnosticator

You are correct.

"I have been able to identify the location of the 4 cam positions sensors - 2 each located on the left & right side of the engine closest to the firewall."

Those are the cam timing actuators that rotate the cams for VVT.

So there are only 2 cam POSITION sensors.... related to error codes P0392 and P0342.
<head slap>

now that begins to make more sense.
I have been reviewing other forums and found references to the 4 sensors near the firewall (timing actuators) and the op referring to changing them and not having P0343 error code cleared.

Now for the next important question... since the code I am getting is P0392, this is the drivers side cam position sensor... is that information correct?

Further, how is this particular sensor removed... is the retaining bolt accessible when the plastic cam pulley cover is removed?

fyi, this info seems contrary to the posting by "nezach" on this audizine post:
http://www.audizine.com/forum/showth...on-Sensor-Help

**audi-owner** · 09-21-2016 07:24 PM

After further research of the error codes, I think I am back at the beginning....
there are 4 Groups of codes related to the cam sensors and the beginning number of each group is:
P0340 – Camshaft position (CMP) sensor A, bank 1 circuit malfunction
P0365 – Camshaft position (CMP) sensor B, bank 1 circuit malfunction

P0345 – Camshaft position (CMP) sensor A, bank 2 circuit malfunction
P0390 – Camshaft position (CMP) sensor B, bank 2 circuit malfunction

all indications are that bank 1 sensors are on the side of cylinder 1, which is the passenger side on the 2002 3.0L
bank 2 sensors are on the side opposite cylinder 1, which is the drivers side on the 2002 3.0L

sensor A refers to the Intake cam
sensor B refers to the exhaust cam.

so unless I am misunderstanding the terminology of "cam timing actuators", the 4 sensors identified in my original post, near the firewall, should be the cam sensors.
the particular error code previously reference - P0392 - should relate to the drivers side exhaust cam sensor (the one closest to the drivers side quarter panel)

In addition, I pulled a connector off of one of the 4 sensors and was able to get a valid part number... the part number appears to translate to a cam sensor...
I don't have the part number right now but I will edit my post later and add it.

Now back to the unknown sensor shown in the pictures.
Unfortunately, when the connector was pulled on those sensors, there was NOT a part number stamped on the side. I checked both of the sensors.

**diagnosticator** · 09-22-2016 02:37 AM

I agree, there is four cam position sensors, but they are at the front of the engine,

"Camshaft Position (CMP) Sensors G40,
G163, G300, and G301
A separate Hall sensor is used to monitor
the position of each of the four camshafts
relative to the position of the crankshaft.
• Camshaft Position (CMP) Sensor G40
• Camshaft Position (CMP) Sensor 2 G163
• Camshaft Position (CMP) Sensor 3 G300
• Camshaft Position (CMP) Sensor 4 G301
SSP255/101
The two sensors required for each
cylinder bank are ganged together in one
housing and mounted at the front of the
cylinder head."

I was mistaken about the VVT cam timing actuators, they are incorporated inside the timing belt sprockets.

Ref: audi.SSP.921103

**john_gonzo** · 09-22-2016 06:05 AM

Originally Posted by audi-owner

The sensor that I am trying to identify is located on the back side of the timing belt access zone and appears to be monitoring the back side of the exhaust camshaft pulley.

Each sensor's electrical connection is coming from the coil pack wiring harness on it's respective side of the engine.

does anyone know what this sensor is?..... thanks...

That is not a sensor.

Originally Posted by diagnosticator

... Those are the cam timing actuators that rotate the cams for VVT.

This is correct. In the images below, note the two SENSOR connectors at one end of the head and the single ACTUATOR connector at the other end of the head behind the cam pulleys. Note the actuator housing curves down to the connector below the level of the valve cover. Both of these images are of driver's side heads.

- - - Updated - - -

Originally Posted by diagnosticator

I agree, there is four cam position sensors, but they are at the front of the engine,

"Camshaft Position (CMP) Sensors G40,
G163, G300, and G301
A separate Hall sensor is used to monitor
the position of each of the four camshafts
relative to the position of the crankshaft.
• Camshaft Position (CMP) Sensor G40
• Camshaft Position (CMP) Sensor 2 G163
• Camshaft Position (CMP) Sensor 3 G300
• Camshaft Position (CMP) Sensor 4 G301
SSP255/101
The two sensors required for each
cylinder bank are ganged together in one
housing and mounted at the front of the
cylinder head."

I was mistaken about the VVT cam timing actuators, they are incorporated inside the timing belt sprockets.

Ref: audi.SSP.921103

D, that information is partially incorrect. The cam sensors are ganged together in a single housing but they are mounted at the BACK of the cylinder head. In that same reference see page 7, bottom figure. The two sensor connectors are visible at the back of the head.

**audi-owner** · 09-22-2016 07:31 AM

thank to everyone for their input. It was a good information exchange. I've been a newbie on other forums (non vehicle) and there seems to be a general lack of interest in helping the new forum members... not true here!

with john's picture help, one can now go back to nezach's post on audizine here:
http://www.audizine.com/forum/showth...on-Sensor-Help

we can see on the exploded parts diagram that the "single housing" for the cam sensors is item 22
unfortunately nezach didn't include a complete parts list, but with the addition of john's pictures, it is clear that item #3 on the parts diagram is the VVT actuator.

**SJorge3442** · 09-22-2016 07:43 AM

Originally Posted by audi-owner

thank to everyone for their input. It was a good information exchange. I've been a newbie on other forums (non vehicle) and there seems to be a general lack of interest in helping the new forum members... not true here!

with john's picture help, one can now go back to nezach's post on audizine here:
http://www.audizine.com/forum/showth...on-Sensor-Help

we can see on the exploded parts diagram that the "single housing" for the cam sensors is item 22
unfortunately nezach didn't include a complete parts list, but with the addition of john's pictures, it is clear that item #3 on the parts diagram is the VVT actuator.

This is all great stuff. Loving seeing this. The 3.0 guys have been on a ROLL recently with good info.

The reason there's only one actuator per head for the VVT is that this device only works as a on/off switch. Once the VVT kicks in, its all or nothing for timing adjustment (I believe its a 22 degree advance). Another 3.0 member, "Zimbu" has been tuning his 3.0 on his own and for a long time was trying to get this sensor to work in a true variable fashion, but after talking to folks over at NefMoto (Me7 tuning website), it was determined that this actuator can not do that. Its all or nothing. Think about it as the way VTEC works on a honda. Once oil pressure hits a certain level, those cams get locked down further and there is more movement from the cams than when the VTEC hasn't "kicked in". Not trying to compare our car to the archaic technology that is VTEC, but its very similar.

**john_gonzo** · 09-23-2016 06:30 AM

Originally Posted by SJorge3442

This is all great stuff. Loving seeing this. The 3.0 guys have been on a ROLL recently with good info.

The reason there's only one actuator per head for the VVT is that this device only works as a on/off switch. Once the VVT kicks in, its all or nothing for timing adjustment (I believe its a 22 degree advance). Another 3.0 member, "Zimbu" has been tuning his 3.0 on his own and for a long time was trying to get this sensor to work in a true variable fashion, but after talking to folks over at NefMoto (Me7 tuning website), it was determined that this actuator can not do that. Its all or nothing. Think about it as the way VTEC works on a honda. Once oil pressure hits a certain level, those cams get locked down further and there is more movement from the cams than when the VTEC hasn't "kicked in". Not trying to compare our car to the archaic technology that is VTEC, but its very similar.

Yeah, I second that - always good to come in here and learn something. Speaking of that, I've been skimming through the reference diagnosticator mentioned back in Post #10.

It's true the exhaust cams have the on/off 22-degree advance but the intake cams are continuously variable from 0-42 degrees. Those two black cylinders standing behind the cam pulleys are the solenoid valves. One for intake, one for exhaust. The acutators are within the pulley hubs. The variable range for the intake cam is controlled by a PWM signal (Pulse Width Modulated) injected into the connector that started this whole thread.

PWM voltage ---> _____|-|_______|-|_______|-|___|------|__|------|__|------|_
Narrow pulses would advance the cam a little bit. Wide pulses, advance closer to 42 degrees.

The intake actuator contains a mechanical detent that returns the pulley to a default position whenever the engine is off (zero oil pressure). That's why when we are installing a new timing belt, we use special socket T40028 only on the exhaust pulleys.

Thread: help identify this sensor on A4 quattro 3.0L engine

Thread Tools

Display

help identify this sensor on A4 quattro 3.0L engine

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions