Monday, August 13, 2012
Volkswagen Jetta TDI 2.0L 18895 P2463 009315
VEHICLE: 2009 Volkswagen Jetta TDI 2.0L, L4, MFI, DOHC, Eng Desg CBEA
18895/ P2463 /009315 - Diesel Particle Filter: Excessive Soot Accumulation
16928/ P0544 /001348 - Exhaust Gas Temperature Sensor G235 Circuit Bank 1 Sensor 1
1. Start by verifying function of the G235 Exhaust Gas Temperature Sensor 1. Failure of exhaust gas temperature sensor function can result in false Diesel Particulate Filter (DPR) soot load codes.
2. The G235 Sensor measures exhaust gas temperature pre-turbo. Using A Volkswagen compatible scan tool, select Measured Data Blocks and then Display Group 99. Display Group 99 will display 4 fields as follows:
Field 1 = Engine RPM
Field 2 = Pre-Turbo Temperature Sensor in Degrees Centigrade
Field 3 = Pre-Particle Filter Temperature Sensor in Degrees Centigrade
Field 4 = Post Particle Filter Temperature Sensor in Degrees Centigrade
3. With the engine fully cooled to ambient temperature, observe the temperature readings from Display Group 99. All exhaust gas temperature readings should be at or near ambient temperature (example: display of all sensors should read at or near 20 degrees centigrade at 68°Fahrenheit ambient temperature).
4. If the G235 Sensor does not indicate a correct temperature value, a sensor or wiring harness fault is the most likely cause.
5. Inspect the wiring harness for damage. The sensor is located on the turbo housing. The wiring harness will have a Brown ground wire (connector T2bz/1) and a red signal voltage wire (connector T2bz/2). Disconnect the harness and observe the temperature reading in Display Group 99 field 2. If the temperature reading changes when the harness is unplugged, the problem in the circuit is with the G235 sensor itself.
6. The G235 sensor has been prone to cracking of the exhaust gas sensing element in the exhaust stream. Remove the sensor and inspect for sensor mechanical damage/failure.
7. Once the G235 fault has been repaired, clear all trouble codes and test drive the vehicle to verify that no codes return.
8. If the 18895/P2463/009315 - Diesel Particle Filter: Excessive Soot Accumulation code returns, see the Tech Tips section for checking DPF soot loading.
Exhaust Gas Temperature (EGT) Sensor G235
Exhaust Gas Temperature (EGT) Sensor G235 Wiring
Diesel Particulate Filter
Diesel Particulate Filter Regeneration Procedure
Replaced Exhaust Gas Temperature (EGT) Sensor G235
Note: Diesel particulate filter soot load can be observed using a full function Volkswagen Compatible scan tool. Select Measured Data Block and then Display Group 108 (Note: if display group 108 does not contain data try display group 241 as an alternate).
Field 2 displays the calculated DPF soot load and Field 3 displays the measured soot load of the DPF in grams.
If either the calculated or measured soot mass is above 30g but below 40g you can initiate a regeneration while standing (idle will be raised etc.), a forced regeneration while driving is also possible. Once the values are above 40g (but below the max 45g) the regeneration while standing is no longer available and the regeneration while driving must be performed. NOTE! If the particle filter load is above specification (45 grams) the particle filter needs to be replaced since the car may burn down when regenerating.