My engine: 3.0 V6 TDI CATSA (225 bhp)
I noticed the occasional hesitation on acceleration (a "hiccup") but no fault codes were shown. Last week, the MIL/CEL came on, VCDS showed the fault code in the title.
I researched the fault code as it relates to the 3.0 TDI engine and found either sparse information or depressing stories of how difficult a job it is.
While the car remains immensely drive-able with this code (no glow plug light flashing) it will no longer run regeneration cycles as long as the fault code is stored. This is bad news for your DPF/particle filter and will cause issues down the line.
So, it needs to be fixed.
Here is my experience:
Braced for the worst, it turned out to be a one hour job. Not bad, maybe a bit hard on the back, that's all.
1) with the VCDS fault code already indicating what the problem is, confirm that the sensor, which sits pre-turbo, is really the culprit.
![Image]()
![Image]()
The sensor is available online and from the parts counter; prices seem to vary, somewhere around $149 US.
Grab the tools needed to do the job. Or, more precisely, grab one and make the other.
![Image]()
You need a T30, preferably with a 1/4 inch ratchet, to get to the three Torx screws that hold the heat shield. Remove the heat shield.
The sensor has a 17mm hex nut holding it in. I bought a cheapo 17mm/15mm double ended flare wrench (used for brake lines) and cut the 15mm end off (round the edges so you avoid bleeding later on). The wrench as-is was simply too long for the restricted space available. There is a special tool, if you prefer (see below).
Now slide the slotted opening of the flare wrench over the sensor "pipe", slide it down over the nut and loosen the nut. Mine did not budge with hand pressure alone. I put the wrench on so that it stood almost vertical, pressed a piece of 2x4 against it and gently whacked it with a steel mallet a few times. The shock loads did the trick, nut came loose, no drama.
![Image]()
If your hex nut does not come loose, you can use the VW special tool (available, for example, from IDparts): EGT Sensor Socket - T40055 - IDP1066 - IDParts.com
or you take a 3/8 drive 17mm deep socket, preferably an impact socket, and a grinder and cut the socket to resemble the special tool.
Another method I read (and have not needed and cannot confirm) is to cut the wire where it enters the "pipe", then grab the pipe and bend it back and forth about 20-30 times until it snaps off flush with the hex nut. Then you can get a regular 17mm socket on and break the nut loose. Do not forget to pull the sensor remnants out, once the nut is loose. But - in my case, none of the drama was needed.
Old sensor and new sensor
![Image]()
Install new sensor
![Image]()
I do not plan on ever removing the sensor again, but nevertheless, if I had to, I could, because a bit of high-temp anti-seize (the copper based one) will prevent the sensor and nut from seizing up. Good to 1200 degrees.
Route the wire the same way as the old one, take the multimeter and measure sensor resistance just to be sure.
Put everything back together.
Clear fault code, start engine and be happy that
![Image]()
I noticed the occasional hesitation on acceleration (a "hiccup") but no fault codes were shown. Last week, the MIL/CEL came on, VCDS showed the fault code in the title.
I researched the fault code as it relates to the 3.0 TDI engine and found either sparse information or depressing stories of how difficult a job it is.
While the car remains immensely drive-able with this code (no glow plug light flashing) it will no longer run regeneration cycles as long as the fault code is stored. This is bad news for your DPF/particle filter and will cause issues down the line.
So, it needs to be fixed.
Here is my experience:
Braced for the worst, it turned out to be a one hour job. Not bad, maybe a bit hard on the back, that's all.
1) with the VCDS fault code already indicating what the problem is, confirm that the sensor, which sits pre-turbo, is really the culprit.
- open hood, remove plastic engine cover
- locate two plugs to the left of the oil filter cap, one orange, one black.
- You want to look at the black connector and follow the wire to the back of the engine, between firewall and the heat shield for the turbo (removed in the pic; 3x T30 torx screws), to locate the sensor location. Just run your fingers along the wire as it "disappears". You will feel the wire entering a thin metal pipe that curves about 90 degrees and leads you straight to the hex nut that retains the sensor in the turbocharger's housing. You might be able to see the nut if you stand at the passenger side headlight (the left headlight as seen from the front of the car) and peek down past the turbo actuator rod.
- Now that you are familiar with the lay of the land, unplug the black connector (no tools required; just depress the tab at the top and pull apart) and gently wiggle the connector out of its holding bracket.
- With a multimeter set to resistance, read the resistance between the two pins in the connector. If the sensor is dead, it likely reads "open" or a resistance of "1". A new sensor mounted in the still still warm (not hot) engine will read around 0.254 Ohms. If your sensor reads open and a scan tool shows an exhaust temperature of 1000 degrees for this sensor, while the others are at about ambient temperature (with engine off and cold), you confirmed that this is really the dead sensor.
The sensor is available online and from the parts counter; prices seem to vary, somewhere around $149 US.
Grab the tools needed to do the job. Or, more precisely, grab one and make the other.
You need a T30, preferably with a 1/4 inch ratchet, to get to the three Torx screws that hold the heat shield. Remove the heat shield.
The sensor has a 17mm hex nut holding it in. I bought a cheapo 17mm/15mm double ended flare wrench (used for brake lines) and cut the 15mm end off (round the edges so you avoid bleeding later on). The wrench as-is was simply too long for the restricted space available. There is a special tool, if you prefer (see below).
Now slide the slotted opening of the flare wrench over the sensor "pipe", slide it down over the nut and loosen the nut. Mine did not budge with hand pressure alone. I put the wrench on so that it stood almost vertical, pressed a piece of 2x4 against it and gently whacked it with a steel mallet a few times. The shock loads did the trick, nut came loose, no drama.
If your hex nut does not come loose, you can use the VW special tool (available, for example, from IDparts): EGT Sensor Socket - T40055 - IDP1066 - IDParts.com
or you take a 3/8 drive 17mm deep socket, preferably an impact socket, and a grinder and cut the socket to resemble the special tool.
Another method I read (and have not needed and cannot confirm) is to cut the wire where it enters the "pipe", then grab the pipe and bend it back and forth about 20-30 times until it snaps off flush with the hex nut. Then you can get a regular 17mm socket on and break the nut loose. Do not forget to pull the sensor remnants out, once the nut is loose. But - in my case, none of the drama was needed.
Old sensor and new sensor
Install new sensor
I do not plan on ever removing the sensor again, but nevertheless, if I had to, I could, because a bit of high-temp anti-seize (the copper based one) will prevent the sensor and nut from seizing up. Good to 1200 degrees.
Route the wire the same way as the old one, take the multimeter and measure sensor resistance just to be sure.
Put everything back together.
Clear fault code, start engine and be happy that
- fault code is gone
- you saved yourself about $600 (that is what I was quoted over the thumb for the repair
