P1219 and P1578, Potentiometer Accelerator

[997_986]

Out of the blue, I’ve got these two faults. I replaced the pedal sensor with a working one for test purposes, but that didn’t sort out the problem. The car is very difficult to start (feels like no cold start function), then runs at just over 1.000 rpm without responding to the accelerator.

What can I do, any tests you recommend? Might it be an electronic problem? How to diagnose that?

What I did before was changing all 4 lambda sensors, smoke tested the plenum (no leaks) and changed the oil. This should have no impact at all to the faults. No more faults are stored.



Car is a 2001 "S" 986

[redpepperracing]

Check the connector at the throttle body as well as the ECU. When you turn the key on it should cycle the TB. I had an issue with mine and I don't know what fixed it exactly as I checked everything I could, but after unplugging and re-plugging the ECU it started working again.

[997_986]

Thanks for the suggestions, I did that 5min ago, I unplugged all plugs at the ECU and the one on the throttle. After reconnecting, checking the seating etc. I connectet the battery and found the same odd failure with durametric again. The flap of the throttle was cycled 1x after ignition on and that's it. Don't know if that is normal. The 2.7 starts calibrating after ~30s and keeps this whistling sound. The behaviour of the 3.2 is different. I do not know if that is normal!

I then started the car which ran at 1.200 1/min with the second try. No possibilities to impact anything with the pedal.
I don't know where to start now, really dissapointed. I think it's time for a PIWIS

[redpepperracing]

I think all of the TB's are the same, it should cycle at ignition, and then if you leave it alone (don't touch anything) it should cycle completely again. And if it's not whistling, it's not working. I have used 986, 996 and 997 TB's and they all behave this way in normal operation. You might have a bad TB? I never got to the point of really troubleshooting as it just 'started working' for me.

[997_986]

These values ar from a working Boxster 2000 2.7L


And these values from that "S" that's not running...


Is it possible that the poti + TB fail at the same time when the car was not moved? And as described, I changed the poti against each other which did nothing. It is even not possible to clear these faults!

Recommendations what I should do next?

[tcoradeschi]

There are a bunch of values there which make no sense at all, so I am leaning toward an ECU issue.

Both the pedal and the TB have potentiometers. Disconnect them and measure the actual resistances. I’m guessing that the values for the S wiill fall inline with those for the Base.

What do do at that point is unclear to me, TBH.

[997_986]

ECU is on it's way to a specialized guy for testing. I've had enough.