1999 V70 P0171 & dipping rpm

JeffHicks · Post by **JeffHicks** » 15 Dec 2013, 21:51

Buncha thoughts & questions here.

For about a week now I've been throwing the P0171 code on my non-turbo FWD base V70. I'll clear the code but it comes back on within a few miles of driving.

From what I've been reading, here and elsewhere, it seems that the most likely culprits are a vacuum leak, bad O2 Sensor(s) and/or bad MAF Sensor. Does that sound right?

Also, sometimes (but not too often) when I come to a stop sign the rpms will drop almost to a stall, then come back up and settle at about 88 rpm. When it does that, sometimes it bogs on acceleration as if it's starving for fuel.

Anybody got any sure bets for me, so that I don't have to spend a bunch of time scratching my head & grumbling?

Also, if I do replace either or both O2 Sensors, is there a brand & part number I want to get? Or a specific brand I want to stay away from?

Thanks so much guys!

For what it's worth, here's the "Freeze Frame" information my scanner gave me.

DTC for which Freeze Frame was Stored P0171
Fuel System 1 Status Open Loop
Fuel System 2 Status Not Supported
Calculated LOAD Value 18.43 %
Engine Coolant Temp 177.80 °F
Short Term Fuel Trim - Bank 1 -8.59 %
Long Term Fuel Trim - Bank 1 49.22 %
Intake Manifold Absolute Pressure 8.88 inHg
Engine RPM 734.25 rpm
Vehicle Speed Sensor 12.43 mph

Post by **rmmagow** » 16 Dec 2013, 07:08

Check the hoses/connections for the Idle Air Control valve. Located near the throttle body. Probably have a split hose. Check thoroughly via remove and flex to look for cracks.

Post by **mikealder** » 16 Dec 2013, 11:28

Take the ETM (Electronic Throttle Module) off and clean it out with a rag soaked in carb cleaner, if this doesn't fix it the ETM might be on the way out because they do fail due to them being a crap design, there is no IACV on a 99 as it has an ETM.

Also on the opposite side of the inlet manifold to where the ETM is located is a small vac hose in the middle of the inlet manifold scroll, check this isn't damaged, it is part of the PCV system and when it breaks it can cause erratic idle - Mike

JeffHicks · Post by **JeffHicks** » 16 Dec 2013, 19:21

Thanks for the help guys!

I spent part of the day trying to find any vacuum leaks - by looking, by listening, and by spraying carb cleaner around any and every tube & connection. Nothing seems obvious at this point.

I also moseyed down to a local U-Pull-It Salvage yard, and paid $25 for a MAF Sensor and upstream O2 Sensor. The upstream O2 Sensor is very easy to change out, so I am basically doing a $5 experiment before dropping $150 for a new one. I know it's a crap-shoot, but for $5 I'm willing to try it. Besides, I don't have a multi-meter to really check & see if the O2 Sensors are working.

Mike, you mentioned the ETM. Is that the throttle-body that is directly attached to the drivers's side end of the intake manifold - connected by the large tube to the MAF Sensor?

Below is a picture of an engine identical to mine. NON-Turbo.

Post by **mikealder** » 17 Dec 2013, 01:11

JeffHicks wrote:Mike, you mentioned the ETM. Is that the throttle-body that is directly attached to the drivers's side end of the intake manifold - connected by the large tube to the MAF Sensor?

Yes, that's the ETM, takes about 20 mins to clean it, just unbolt it don't take it out of the engine bay as its cable is trapped between the starter motor and the engine block - Mike

kirstyp · Post by **kirstyp** » 28 Oct 2015, 10:52

Hi, I have the same symptoms on my 2001 v70 driving me bonkers, have changed, spark plugs, maf, 02 sensor, changed the oil trap, got a yellow sticker etm which has the sacer fix works fantastic, just plug and play! No reload! Air filter oil change and filter new fuel filter but still I have erratic idle, just wondering did you ever sort this? Oh new coils

Post by **abscate** » 29 Oct 2015, 00:01

kirstyp wrote:Hi, I have the same symptoms on my 2001 v70 driving me bonkers, have changed, spark plugs, maf, 02 sensor, changed the oil trap, got a yellow sticker etm which has the sacer fix works fantastic, just plug and play! No reload! Air filter oil change and filter new fuel filter but still I have erratic idle, just wondering did you ever sort this? Oh new coils

You've got a vacuum leak. Grab your vacuum diagram and check all the hoses by removing and looking for holes and splits. If you look at them while they are on the car, you won't find the leak.

janelholt · Post by **janelholt** » 30 Jan 2017, 13:22

Hi
I have a Volvo XC70AWD With a faulty ETM resulting engine not running clean at all..no response from gas pedal..
Found a used one from an working volvo S80 With exactly same sticker (yellow) and same numbers.

Car starts up fine and idling is Perfect.. only not responding on gas pedal.. or very slow like Power is reduced (Limp mode)

Is there anyone who can assist on reloading software to the New ETM. I have a Vida Dice unit
Thanks

Brgds
jan

Post by **wizechatmgr** » 30 Jan 2017, 14:57

I believe the ETM software has to be loaded after swap. Can anyone confirm/deny this?

janelholt · Post by **janelholt** » 30 Jan 2017, 15:18

You are probably right, the ETM software need to be loaded again. Is there anyone who can assist on doing this remotely through temviewer or something similar?
I belive its also an old software on the ECM, because the ETM test cannot be done through Vida Dice due to no old software (Pre 2006)
Anyone that could please help me getting the car running again?

Thanks
Brgds
Jan