Touran tdi dpf sensor nightmare

**ryanp29** · 10-05-2017,07:34 PM

Hi, I've got a touran 2.0 tdi 170 bmn, it's currently stuck in limp mode, it started with the dpf light coming on, so as soon as I could I took it on the motorway for a blast, however as I got to a suitable engine speed, I put the cruise control on and a few seconds later the coil light and EML came on and she went into limp mode, next day a mates code reader came up with - 08194 particulate trap bank 1 below efficiency threshold P2002 short with power, so then I took it to a garage to confirm the code and get a professional opinion and as I first thought, he thought the same - dpf pressure sensor, fitted a new one and now I still get the same code, he tried taking it for a drive and performing a regen, but it's still the same! He then suggested a short or damaged wires, I've checked the wires and after a few resistance checks they all appear fine, however I've still got the same problem. Although if I disconnect the dpf pressure sensor, the coil light disappears and the car drives normally??? With the EML and dpf light still on?
Anyone got any ideas? It will be very much appreciated

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**Flash2** · 11-05-2017,11:02 AM

Originally Posted by ryanp29

Anyone got any ideas? It will be very much appreciated

Did the guy in the garage confirm the correct voltages were present at the sensor? With the sensor connected and the ignition on, use a pin/needle to back probe each wire on the sensor connector and measure the voltage on the wire. You should have one with 5V (power supply), one with 0.5V (signal to ECU) and one with < 200mV (earth). Once you've confirmed that's correct connect the meter to the signal wire again and start the engine. The signal voltage shouldn't change by much when the engine is started...if the particulate trap is clear.

I found this video on youtube showing DPF sensor voltage measurements before & after a regen :

**ryanp29** · 11-05-2017,11:18 AM

No mate he never tried this, but I will tonight after I get home from work.
Many thanks for your help with this.

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**Crasher** · 11-05-2017,01:00 PM

18434 (P2002) 008194 - Particle Filter Bank 1: Malfunction

There is no suggestion of a wiring fault or problem with the sensor, you only have one code. You need to use advanced measuring blocks to see what the Ash Mass figure is, if it is above 60g the DPF will need either cleaning or replacing. Cleaning allows you to reduce the ash mass figure to 50% of maximum, not 0.

**ryanp29** · 11-05-2017,01:18 PM

Hi Crasher, I'm not sure but I think because the code reader said short with power, as well as particulate trap below efficiency threshold and that he replaced the pressure sensor and the same fault came up afterwards and he attempted to delete the fault code unsuccessfully, is why he suggested a wiring fault??

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**Crasher** · 11-05-2017,05:42 PM

So there is another code?

**ryanp29** · 11-05-2017,05:44 PM

Only codes are p2002 and 01894

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**ryanp29** · 11-05-2017,05:57 PM

Only codes are p2002 and 01894

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**Crasher** · 11-05-2017,09:55 PM

18434 (P2002) 008194 - Particle Filter Bank 1: Malfunction

P2002 and 01894 are the same code as is 18434, just different standards and there is no wiring issue hinted at and it is not the EGT sensor...

18434/P2002/008194 - Ross-Tech Wiki

**ryanp29** · 11-05-2017,10:08 PM

Thanks, he did say that the sensor was not giving any load readings, although he did replace it with a genuine one from VW and managed to do a regen whilst driving with his kit connected to the obd ,could a blocked dpf be the cause? The code reader did say short with power, I thought that could mean a electrical issue?

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