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

bobice · Post by **bobice** » 13 Jun 2010, 17:41

Hi,

My 2000 volvo V70 XC at 168000 Miles has been running fine after replacing Thermostat and Engine Coolant Sensor a few weeks ago, but today when my friend was driving at 68 miles an hour and trying to pass another vehicle, the car suddenly lost power. After restarting, the engine jumps between 500 to 2000 rpm, no power, with Flashing arrow and Check Engine light. After towing it back to home, I found the codes are:
P1238 Turbo Control Valve,
Freeze Frame Data: Fuel Sys 1: CL;
Cal Load (%): 70.9;
ECT (F): 221;
STFT B1 (%), 25;
LTFT B1 (%), 0.7;
Eng RPM: 3040;
Veh RPM, 68 Mph;

and
P0134, O2 Circuit No Activity Detected (Bank 1, Sensor 1),
P0101, Mass or Volume Air Flow Circuit Range/Performance.

Tried searching this site, but didn't find a cause yet. But one post mentioned about the fuel injector problem. When I replaced Engine Coolant Sensor, I was trying to take off the Fuel Rail, but only disconnected the connector that looks like a electronic connector, and I noticed that one is loose - others can be clicked tight. I guess I should start from replacing the injector connector?

Please help me diagnose the problem, Please! Is it going to cost me a fortune to fix it? Already spent a lot of money and time on the car. Couldn't afford another big one. : (

Appreciate your help.

Post by **polskamafia mjl** » 13 Jun 2010, 18:23

I know very little about the later Volvo models but the P0101, Mass or Volume Air Flow Circuit Range/Performance code sounds a little like a MAF problem. So my advice would be to disconnect the MAF and see what happens. Hopefully your idle will drop to normal and everything will be ok.

bobice · Post by **bobice** » 13 Jun 2010, 19:12

polskamafia mjl wrote:I know very little about the later Volvo models but the P0101, Mass or Volume Air Flow Circuit Range/Performance code sounds a little like a MAF problem. So my advice would be to disconnect the MAF and see what happens. Hopefully your idle will drop to normal and everything will be ok.

I just disconnected MAF under a flash light, and now the engine idles fine. Does this mean MAF sensor is bad, and all I need to do is to order a new MAF?

Thanks for your advice!

Post by **boosted5cyl** » 14 Jun 2010, 14:29

Yep, its likely the MAF. If you agve a mean to, monitor the g/s channel from the MAF with your OBD tool and see if there are any variances at idle.

Post by **polskamafia mjl** » 15 Jun 2010, 14:26

Yes, you just need a new MAF. Make sure it is a Bosch unit though! After market ones won't work.

bobice · Post by **bobice** » 15 Jun 2010, 22:04

Thanks! I ordered a new Bosch part from ebay for $52 - sadly, it turned out to be an item not labeled with Bosch! Did not work.
Have to find one elsewhere.

But I have two questions:
1, can I drive with the MAF wire dis-connected?
2, Is there a clamp (like hose clamp) to hold tight the MAF sensor with the intake tubing? There is no clamp on my V70, but I'm afraid it's missing.

Post by **Ozark Lee** » 15 Jun 2010, 23:13

2, Is there a clamp (like hose clamp) to hold tight the MAF sensor with the intake tubing? There is no clamp on my V70, but I'm afraid it's missing.

Yes there should be a hose clamp on both sides of the MAF to seal it.

...Lee

bobice · Post by **bobice** » 18 Jun 2010, 16:01

When the MAF sensor (Bosch and same as the original) came from FcpGroton.com, I immediately put it in. But the engine still idles cycling from 500 to 1500 rpm within 1 second or 2. After disconnect the MAF sensor, engine idles at 900 rpm, and I can drive the car a little bit. I'm thinking to test drive at higher speed.

I could try to get an replacement of MAF sensor from FcpGroton, but before doing that, I just wonder what else can cause my problem? Is there a relay or something else could go bad? How to test the MAF sensor?

Many thanks.

bobice · Post by **bobice** » 20 Jun 2010, 12:12

After put in the new MAF sensor, the engine still cycles from ~200-1000 rpm (frequency at ~ 2 seconds). When I press the gas pedal, the engine can turn faster. Now there is only one code left: P1238

What could be the problem? Shall I replace the turbo control valve and the vacuum hose? I do notice that the vacuum hose seemed to be original and the rubber feels like powder now.

Anybody tried the tubro control valve from IpdUSA.com? It is much cheaper than Volvo parts, and they have a nice instruction on how to replace the valve.
The link is
http://www.ipdusa.com/Volvo-S60/Engine- ... -395-4235/

bobice · Post by **bobice** » 26 Jun 2010, 19:19

Here is the update,

First I changed the MAF sensor, the car still cycles at 500-1000 rpm, but the MAF sensor code is gone, only P1238 remained.
So I started to read about the MAF sensor and the whole intake system, and turbo. At this point, I found that there is a vacuum hose connecting the fresh air pipe and the pipe going to throttle body was disconnected, I put that back on. The problem persisted. There was no spring Clamp on the vacuum hose.

Since P1238 is for the TCV valve, I tried to replace it with a used one from ebay before spending $500 on the throttle module and time to take it out. The engine still cylces between 500-1000, but the code P1238 is gone.

Then today I finally lied down under the car, and found that the turbo pipe was loose from the radiator. I secured it, BINGO! Now the car finally went back to normal. The turbo pipe was attached with two small plastic hose clamps!

Two weeks ago, I had the lower coolant pipe replace by a local shop - thought he was nice, but now I think he intentionally did not put the clamps back on and used the plastic string instead of metal clamp. I almost went back to him after two-week of stress of dealing with my car. Good thing is that now I'm very clear about the ETC modules, MAF Sensor, and the air intake system!

Thanks for all of your advice!