Hi, my first post so thank you for adding me. I bought a TwinAir 4x4 from an eBay trader earlier this year which against my better judgment I had delivered and has turned out to be a complete PITA, although when actually working drives really well. It's done nearly 100k miles and I have some history.
Anyway, to try and cut a long story short I bought this for a charity trip to the Arctic this winter. As soon as I drove it further than down the street it was virtually undriveable with it entering a limp mode with high restricted power and rpm. I'll try and summarise it below in bullets:
- Multiple problems prior to my ownership (not aware at purchase) with “limp mode” / “total loss of power”
- DTC codes for knock sensors had seemingly led to the knock sensor being replaced multiple times. A local mechanic to me also replaces the knock sensor and it does not fix it.
- I drive it and experience a similar thing. No CEL at any point although the CEL on the dash still illuminates and goes out during startup as normal
- Take it to a proper old school motor engineer and we start working on the car
- DTC codes P0325-12 and P1325-49
- Investigate wiring; poor oscilloscope trace so remove old wiring and replace entirely including new earth etc. Oscilloscope trace now ok. Change oil correct for twinair engine plus various other works / diagnostics to eliminate other problems.
- Car seems to drive ok for at least 150 miles but knock sensor DTCs can only be cleared by Snap-On whilst engine running, not with ignition only
- Driveability problems return: no extreme limp mode but significantly reduced performance suggesting restriction by ECU occurring intermittently. Still no CEL.
- Transpires ECU has already been sent to ECUTesting and they could not interrogate it
- Took it to a local ECU specialist who could not find any fault with the ECU including the knock sensor circuit
- Put ECU back in and notice on start-up as if on one cylinder for 10s or so. Battery ok.
- Replace knock sensor again just in case with Bosch sensor, re-check wiring
- Change oil again with correct grade oil and also change UniAir oil strainer
- This time run MES rather than Snap-On and manage to clear knock sensor codes. Perform phonic wheel relearn
- Test drive and restricted timing / limp mode returns but still no CEL. Return and only knock sensor code P0325-12 showing. Clear code again successfully.
- Then use MES to reset all learned parameters and oil change reset
- Test drive again and drives well although knock sensor code P0325-12 showing on MES again
- My mechanic suspects UniAir module is on the way out ?losing oil from chamber seals and this has been what has triggered knock sensor codes all along. Probably not been serviced properly in the past and has done quite a few miles.
So, if you've read all of this sorry tale..... Do you think this could be a UniAir module issue (no other codes aside from C2005-68 for the ELD although I have demonstrated it sends power to the rear wheels)?. Other things to note is that the gear shift indicator (it's a manual, I mean for economy) hardly ever works, the start/stop never works (but doesn't say it's faulty on the dash), and some of the steering wheel buttons do not work.
I'm going to give it an extended period of testing as I am running out of time to get this car prepped (we have also done the rear driveshafts, the exhaust, fluids etc etc) but the worst thing would be changing the UniAir module and it not actually being the issue.
Thanks, and hopefully I can actually post some pictures of the car and the trip......!
Anyway, to try and cut a long story short I bought this for a charity trip to the Arctic this winter. As soon as I drove it further than down the street it was virtually undriveable with it entering a limp mode with high restricted power and rpm. I'll try and summarise it below in bullets:
- Multiple problems prior to my ownership (not aware at purchase) with “limp mode” / “total loss of power”
- DTC codes for knock sensors had seemingly led to the knock sensor being replaced multiple times. A local mechanic to me also replaces the knock sensor and it does not fix it.
- I drive it and experience a similar thing. No CEL at any point although the CEL on the dash still illuminates and goes out during startup as normal
- Take it to a proper old school motor engineer and we start working on the car
- DTC codes P0325-12 and P1325-49
- Investigate wiring; poor oscilloscope trace so remove old wiring and replace entirely including new earth etc. Oscilloscope trace now ok. Change oil correct for twinair engine plus various other works / diagnostics to eliminate other problems.
- Car seems to drive ok for at least 150 miles but knock sensor DTCs can only be cleared by Snap-On whilst engine running, not with ignition only
- Driveability problems return: no extreme limp mode but significantly reduced performance suggesting restriction by ECU occurring intermittently. Still no CEL.
- Transpires ECU has already been sent to ECUTesting and they could not interrogate it
- Took it to a local ECU specialist who could not find any fault with the ECU including the knock sensor circuit
- Put ECU back in and notice on start-up as if on one cylinder for 10s or so. Battery ok.
- Replace knock sensor again just in case with Bosch sensor, re-check wiring
- Change oil again with correct grade oil and also change UniAir oil strainer
- This time run MES rather than Snap-On and manage to clear knock sensor codes. Perform phonic wheel relearn
- Test drive and restricted timing / limp mode returns but still no CEL. Return and only knock sensor code P0325-12 showing. Clear code again successfully.
- Then use MES to reset all learned parameters and oil change reset
- Test drive again and drives well although knock sensor code P0325-12 showing on MES again
- My mechanic suspects UniAir module is on the way out ?losing oil from chamber seals and this has been what has triggered knock sensor codes all along. Probably not been serviced properly in the past and has done quite a few miles.
So, if you've read all of this sorry tale..... Do you think this could be a UniAir module issue (no other codes aside from C2005-68 for the ELD although I have demonstrated it sends power to the rear wheels)?. Other things to note is that the gear shift indicator (it's a manual, I mean for economy) hardly ever works, the start/stop never works (but doesn't say it's faulty on the dash), and some of the steering wheel buttons do not work.
I'm going to give it an extended period of testing as I am running out of time to get this car prepped (we have also done the rear driveshafts, the exhaust, fluids etc etc) but the worst thing would be changing the UniAir module and it not actually being the issue.
Thanks, and hopefully I can actually post some pictures of the car and the trip......!
