Evening All,

Would appreciate some thoughts on this vehicle.

HISTORY Vehicle was purchased about 3 months ago and now has 83,000 recorded miles. During that time, the vehicle developed a fault and the dealer replaced the NOX sensor. Soon after, a gear box mounting failed which was repaired and then the EML illuminated. A VW Specialist declared that it required a new throttle control motor although it had a multitude of fault codes. Customer wanted a second opinion from me.

SYMPTOMS Vehicle will drop into limp mode when driven at about 3000 rpm and the APC warning light will illuminate in addition to the EML light.

TESTS Scanned all relevant sensors and all ok except for post cat lambda sensor which was reading 0.14v. 4 Gas emissions were all within spec. Vehicle behaved well whilst under test.
Vehicle is fitted with NGK plugs and number 2 was inspected and cleaned. Throttle motor plate was carefully cleaned.

FAULT CODES

P2096 Fuel Trim
P2138 Throttle Position sensor
PO688 Throttle Actuator
P2202 Nox Sensor - short to ground
P2201 Nox Sensor - Circuit/range performance
16684 Misfire
16686 Misfire cylinder 2
18354 Coolant Fan?
18528 Post Cat Lambda Sensor - too lean
16575 Fuel Pressure sensor

I have cleared down all the codes and will revisit the vehicle later this week to see what codes have materialised. I am not too familiar with the workings of the NOX sensor but I understand it has its own controller somewhere. I have also read that the NOX sensor on these vehicles have been subject to recall and soft-ware update. I am minded to change the NGK plugs for OEM plugs in view of the problems that can be associated with them. Also, I will need to check for earthing points around the gear-box area.

SUMMARY Basically, I am looking for a "heads up" and thoughts on the points raised prior to my next visit. Hopefully, there will not be a multitude of fault codes to consider!

Regards

Pete M