Idling engine at 500-1500 rpm , code P1238, no power Topic is solved

Post by **polskamafia mjl** » 26 Jun 2010, 20:57

Damn, I was really hoping I was right about something for once. :-/ Oh well. I'm glad you finally got it figure out!

goVolvo · Post by **goVolvo** » 07 Jul 2018, 19:18

Help needed here for my 2000 V70XC 225K miles.
Got same problem, rough idle 600-1000RPM, engine shakes badly. No power, floor the gas pedal and RPM won't go above 2500-3000. Can only drive in parking lot. Occasionally it doesn't happen after restart engine and drives just fine. But this trick seems not working now weather getting hot. Read a pending fault code P1238. Disconnect MAF and nothing changes. Don't want to lose this car. Thanks for any clue.

Reached to the turbo pipe to radiator and it seems attached fine. Other pipes seem fine too.

Post by **RickHaleParker** » 07 Jul 2018, 21:11

ECM-6806 (P2138) Turbocharger (TC) control system flow fault. Flow too low or too high.

Diagnostic trouble code (DTC) information

Condition
If engine speed (RPM) is above 3500 rpm and the engine is operating at a high load, the control signal to the turbocharger (TC) control valve is at maximum and the boost pressure (from boost pressure sensor) is lower than a designated value (approximately 20 kPa (2.9 psi) under normal boost pressure - signal too low).
If the air mass (from mass air flow (MAF) sensor) is higher than a desired value (signal too high) it is interpreted as a fault and diagnostic trouble code (DTC) ECM-6806 is stored.

Substitute value
reduced boost pressure

Possible source
Signal too high:

air leakage after turbocharger (TC)

Signal too low:

hoses between turbocharger (TC) and turbocharger (TC) control valve respectively turbocharger (TC) control valve and pressure servo are loose or are blocked/damaged
faulty turbocharger (TC) control valve
faulty boost pressure control (BPC) valve pressure servo
sticking boost pressure control (BPC) valve

Fault symptoms
none

goVolvo · Post by **goVolvo** » 07 Jul 2018, 21:58

Yeh read about this OBDII code description too. My wild guess maybe the Turbo Control Valve needs to be replaced.

Continue reading.. Found the ipd parts and instruction. Thank god it is just under the air box and I should be able to do it.

Updated today: it starts fine usually at the first drive of the day, or after several hours' parking. However it always shows the problem if starts when engine is still hot. I ordered the Turbo Control Valve online and wish it doesn't go worse while I am waiting for the parts this week.

goVolvo · Post by **goVolvo** » 12 Jul 2018, 20:26

Update: I found it starts fine in morning and drives fine. I park it in shades or covered garage so it is not hot and can start and drive in afternoon again. However problem will happen if car is stopped and it is hot.

Quite frustrated on this. And I am still waiting for the Turbo Control Valve coming in mail next week.

The car is probably not in good shape now. It burns oil. I see smoke when starting it. I also see a few times of transmission slipping, eg, RPM goes up while speed doesn't change. Looks like time to retire it. I am not that handy to tackle engine turbo or transmission problem. I can try replace transmission fluid but that is the best I can do. I can't even drive it to a shop and drive it back.

Post by **RickHaleParker** » 13 Jul 2018, 02:07

I see smoke when starting it.

Black, Blue-Grayish or White smoke? Stand back there as somebody else starts it, does the smoke smell like oil, fuel or does it smell sweet?

goVolvo · Post by **goVolvo** » 13 Jul 2018, 10:35

RickHaleParker wrote: ↑13 Jul 2018, 02:07 I see smoke when starting it.

Black, Blue-Grayish or White smoke? Stand back there as somebody else starts it, does the smoke smell like oil, fuel or does it smell sweet?

I can see it is blue-blackish when wind blows the smoke side way. I had to add 2qt engine oil after about 5k miles or 6 months. So I know it burns oil to some extent. The thing is if it starts and idles fine, then it drives without problem. If it shakes after started (when it is hot in a day or engine is hot), then seems put into limbo mode by ECM and won't drive above 5mph. It seems some checking at start failed. But so far I only get a pending error code P1238 with OBDII reader, no CEL light.

Post by **abscate** » 16 Jul 2018, 08:26

Well at 225k miles you are pretty much due for a throttle body replacement.

2liters of oil every 5k miles is normal consumption for a high miles car (Mod note - please lets not restart that thread)

Ignore that P1238 - if you are in limp mode, all bets are off.

VIDA is the best tool to diagnose a MY 2000 - you can read off the Electronic Throttle Body positions and know right away where you are at.

goVolvo · Post by **goVolvo** » 21 Jul 2018, 10:40

Got a Turbo Control Valve and it doesn't change.

Got VIDA hooked up. After erase all DTC and cycled and read again, only one remains:
ECM Throttle position - faulty current.

The throttle body was a yellow label used one replaced three years ago. Maybe need to get another one.

There is one on ebay with rebuild date in 2013 but the label is still white. Could it be rebuilt with contactless sensor? I thought rebuilt ones are usually yellow label.

https://m.ebay.com/itm/99-02-Volvo-S60- ... 2084412513

goVolvo · Post by **goVolvo** » 28 Jul 2018, 17:32

Got a yellow label one with rebuild date in 2013. Put it on today and seems works fine. Did multiple trips without any issue.

Were those yellow label ones also rebuilt with contactless position sensors and supposed to be long lasting?

The previous one was an old one rebuilt by Xemodex. Unfortunately it only lasted 3 years for me.

Idling engine at 500-1500 rpm , code P1238, no power Topic is solved

Re: Idling engine at 500-1500 rpm , code P1238, no power