CEL P0234 and P2097 Topic is solved

Jonboy74 · Post by **Jonboy74** » 02 Jun 2018, 10:30

Hi all,

Volvo V70 2.4T with 237,855 miles...

Started running a little rough and I thought maybe it was misfiring and I had lost a coil, but after pulling codes, I don't think so.

Got a P0234 Turbo/Supercharger Overboost along with a P2097 Post Catalyst Fuel Trim System Too Rich Bank 1. (using the Torque app for Android)

The P0234 seems to point to the Turbo Wastegate? I'm in over my knowledge level here. Did not find anything in the forums about P2097....

Any ideas to point me in the right direction? I've done a LOT of my own maintenance, but know ALMOST NOTHING about how the turbo works or how to diagnose it properly....

Thanks!

Jonboy

Post by **RickHaleParker** » 02 Jun 2018, 12:24

ECM-6805 (P0224) Turbocharger (TC) control valve, boost pressure fault. Pressure too high

Diagnostic trouble code (DTC) information

Condition
Diagnostic trouble code (DTC) ECM-6805 is stored if the pressure measured by the boost pressure sensor is higher than a calculated desired value. This is interpreted as a fault by the control module. The fault is diagnosed by the control module at high engine loads.

Substitute value
Reduced throttle angle.

Possible source

The hoses between the pressure servo for the boost pressure control (BPC) valve and the turbocharger (TC) control valve have come loose or are blocked or damaged

The hoses between the turbocharger (TC) control valve and the charge air pipe (between the turbocharger (TC) and the charge air cooler (CAC)) are blocked or damaged

The pressure servo for the boost pressure control (BPC) valve is incorrectly adjusted

Faulty pressure servo for the boost pressure control (BPC) valve

Sticking boost pressure control (BPC) valve

Faulty turbocharger (TC) control valve.

Fault symptoms
Poor performance.

--------------------------

ECM-262A (P2097) Long-term fuel trim. Upper limit

Diagnostic trouble code (DTC) information

Condition
The control module receives information from the heated oxygen sensor (HO2S) about the fuel / air mixture when idling at both the lower and upper part-load range. If the fuel / air mixture deviates from λ=1, the short-term fuel trim will compensate for this by adjusting the injection time so that λ=1 is achieved. When the short-term fuel trim makes an adjustment, the integrator median must be adjusted by the long-term trim. Diagnostic trouble code (DTC) ECM-262A will be stored when the long-term trim must be adjusted almost to maximum in the idle range.

Substitute value
none

Possible source

Upper limit:
intake air leakage
exhaust system air leakage
defective heated oxygen sensor (HO2S)

Lower limit:

intake air leakage
high fuel pressure
leaking injectors
defective mass air flow (MAF) sensor
contaminated engine oil
oil level too high
defective heated oxygen sensor (HO2S)

Fault symptoms
none

Jonboy74 · Post by **Jonboy74** » 02 Jun 2018, 15:26

Thanks for the reply.

Ok, that’s a lot of info....not exactly sure where to begin here.

Jon Boy

Post by **oragex** » 02 Jun 2018, 18:48

To check for coils/spark plugs, just undo the injector connectors one by one, pretty much like this (or the coils, but injectors are easier to unplug)

Post by **RickHaleParker** » 02 Jun 2018, 19:25

Start with things that don't cost anything to check.

Intake air leakage
Exhaust system air leakage
Turbocharger hoses.

Post by **abscate** » 03 Jun 2018, 05:02

Clear codes and see what’s comes back.

How old are plugs and ćoils? The coils last about 150k miles , plugs 25-50k depending on type

Jonboy74 · Post by **Jonboy74** » 04 Jun 2018, 21:03

@abscate & @oragex Thanks for the replies. Fairly certain this is not an ignition coil or plug issue, because in the past I have gotten a specific misfire code. Also, I have replaced all but one of the coils in the past several years, and all of the plugs in recent history. I cleared the codes for grins and giggles and the P0234 Turbo/Supercharger Overboost came back.

@RickHaleParker Thanks for your replies as well. I didn't find anything obvious. We had to get a rental because the fuel pump died in our Chrysler. Got it fixed promptly, and SWMBO suggested we just keep the rental another day or so and take the V70 to the shop to let them fool with it, because I don't have time now

I'll post back and let you know what they find.

Post by **abscate** » 05 Jun 2018, 05:01

A charge pipe fault will really upset these cars, I chased a loose clamp at the top of my intercooler for three weeks before letting my indie find it when I was still on the steep learning curve of Volvo.

Jonboy74 · Post by **Jonboy74** » 11 Jun 2018, 20:31

Thanks guys. shop found a vacuum leak and replaced a short section of hose. Also, they said the valve was completely unresponsive and replaced it. codes have not come back.