Boxster 2.5L -MY1999 - Fault codes P0152 / P1115 / P1119

[privateselling]

Hello Loren,

After having bought the Durametric interface I noticed that there are some trouble codes stored in the ECU of my car.

Nevertheless the engine starts well, the car drives fine except for the drive off (now and then heavy clutch judder, especially during stop and go traffic) and fuel consumption is rather low. The CEL never lit !!

According to the literature defect code P0152 may be caused by an airleak or a defective air mass meter.

Do you think this is a plausible reason for this defectcode and why is it only on Bank 2 (cil.4-5-6)?

Would it be helpful to replace the 02-sensor of Bank 2 only ?

I will send you some snapshots by separate mail so that you can evaluate the 02-sensor readings. You will notice that the values of 02-sensor of Bank 2 remains steady. I think this is a 'replacement value' due to the non-proper working of the 02-sensor.

I would highly appreciate your hints. (mind also that it is ROW-car and not a US-version).

Thank you,

Alfred

ECU_defectcodes.PDF

Edited February 5, 2007 by privateselling

[Loren]

Hmm... both O2 sensors lose heating as the same time (P1115 and P1119). I don't think I have seen that - I won't say it's not possible but it does seem unlikely.

I would start inspecting the cables and connectors to the two pre-cat O2 sensors.

Check resistance of O2 heating.

1. Remove connector of 02 1/2 ahead of catalytic converter.

2. Connect ohmmeter on pin side to pins 1 and 2.

Display: 1.8 - 2.5 ohms at 20°C.

3. Connect ohmmeter on pin side to pin 1 and 02 housing.

Display: infinite ohms

If that is okay then go on to -

Check wiring from DME control module to disconnection point of 02 1/2 for continuity, short to B+ and short to ground.

1. Remove connector of 02 1 and 2 ahead of catalytic converter.

2. Connect special tool 9616 to wiring harness (DME control module connector).

3. Connect ohmmeter to special tool 9616, pin 30, and disconnection point of 02 1/2 ahead of catalytic converter, pin 2.

Display: < 1 ohms

4. Connect ohmmeter at sleeve to connector, pin 2, and ground.

Display: infinite ohms

5. Remove ignition, injection and oxygen sensor heating relay and bridge terminals 30 and 87.

6. Connect voltmeter at sleeve to connector, pin 2, and ground.

Display: 0V

[privateselling]

Hello Loren,

Thanks very much for the prompt reply.

I have some additional questions :

1. What do you think about the error code P0152 (on the snapshot you can clearly see that 02 sensor 2 remains at a steady voltage of 0,430mV)?

2. I suppose the special tool 9616 is a specific Porsche tool or is it a common tool available on the market (sort of break-out box ?) ? Price ? Available from ?

3. I suggest I do not have to bridge the relay for the oxygen sensor if I can make sure that I have 12V on pin 1 of the car wiring 02connector with "ignition ON" ?

4. Any idea why the MIL lamp never came on with these three fault codes in the ECU memory?

As I already wrote in my first question the car runs well. Only when going to the yearly car inspection (mandatory by law in Belgium) I can hardly pass the emission test.

Why is it not possible to send you the snapshots (exel-files) through this website. Do you have an email address where I can send it to your attention.

Thanks again,

Alfred

snapshot_engine_1_29012007.PDF

snapshot_engine_2_29012007.PDF

Edited January 30, 2007 by privateselling

[Loren]

1. Did you do the resistance test? That will tell you if the O2 heaters are shorted.

2. Yes, 9616 is just a break out box so that you don't short pins on the DME and kill the DME.

3. Yes, ignition on should work (if I read the schematic right).

4. Two thoughts here - 1. the bulb is burnt out or 2. you might have caught the codes just prior to the DME turning the light on. The DME has to sense a problem that is not being corrected (within a specified engine and/or time cycle) to turn the CEL on.

[privateselling]

Hello Loren,

Your suspicion seems to be very correct !

I measured the resistance of the 02 sensor2 heating cables and I read 24MΩ !! No wonder that the 02 sensor2 did not function.

Replacement of the 02 sensor was (naturally...) not so evident since it was quite stuck in the pre-cat exhaust pipe. I had to dismantle the cat from the car and had to heaten up the 02 sensor to get it out.

Luckily I had a brand new spare 02 sensor available. After replacement of the 02 sensor2 everything works fine, the voltage of both O2sensors switches now as it should be and the engine turns a lot more quiet and steady than before.

The most significant improvement can be felt in the drive-off of the car. I always thought I had a clutch or DMF-problem but now I am convinced that this was caused by the non-working 02 sensor2.

I really drive another and better car now. (I would recommend all members whose car suffer from clutch judder to check for the proper working of the 02-sensors!)

I checked the CEL and it functions with ignition 'ON'. Still wonder why it never lit with these 3 fault codes in the memory of the ECU since the 02 sensor problem must have been present for nearly a year now.

[You can imagine my disappointment in the official Porsche service-shop where my car was in service for approximately 3 years now with an extended warranty contract. I suspect they have seen the failure but since the lambda value remained at 1,00 I think they never mentioned it order not to be obliged to grant me a new 02-sensor or the mechanic was not capable to interprete the engine values on his genuine diagnostic tool, so be aware ...!]

On the other side I was very happy with the purchase of the DURAMETRIC scanning tool which brought this engine failure to my attention so that future engine or catalytic converter failures caused by the defective 02-sensor will certainly be avoided.

I can only recommend this tooling to other enthusiasts.

Many thanks for your professional help in solving this problem. Of course this will result in a donation from me to the RennTech organisation.

Keep on this constructive work, it is highly appreciated ! :clapping:

Best regards from Belgium,

Alfred

Edited February 5, 2007 by privateselling