Intermittent Acceleration Issues - Need Help

[jderosa3]

My wife and I just bought a 2001 Volvo V70 XC AWD 2.5T off of a personal owner. This person was the 2nd owner and had paper work to prove it's maintenance and various other jobs done to the vehicle over time.

It has roughly 150K on it and is in great physical condition - I know the physical condition itself doesn't mean much but it does tell a story about who owned the car.

Anyways. We had the car for about a month. Everything was running fine. Not an issue at all.

Since having the car - the only thing I personally have done to the car was the following:

• Used Seafoam cleaner to make sure the fuel system was clean. Did this as soon as we got the car.
• After running the Seafoam. We used a bottle of Lucas upper cylinder lubricant. Both were ran through a full tank of premium fuel.
• Changed the oil and filter with Castrol Syntec Edge Synthetic oil 10w-30. Recommended weight by Volvo.

I can't see why the above... especially after going through at least 5-6 tanks of fuel would cause the issue we are experiencing.

What has been happening is the vehicle will out of nowhere drop to 2K RPM and will not rev past that amount - it will bounce between 2100 and back down to 1800... it will keep doing this if you hold the gas down far enough. It has lower power at this point...

This is intermittent - it has happens 3 times in the last week. You can go 5 miles or 60 miles (distance) before this happens (when it does occur).

We had original thought this could be fuel cap related, but just tonight when this happened again. I shut the car off... turned it back on and the issue was gone. In all three cases I was going to scan for a code, but the engine light went off in all three cases before I could read the code. Very aggravating.

I can't say for sure - but I want to believe that the temperature outside when these occurrences happened have all been below 35 degrees. This could just be wishful thinking to find an answer to this problem.

I plan to replace the following when weather permits:

• Fuel Filter
• Fuel Cap

Could the filter possibly be the issue? Or could this be spark plug related? Without a code I am at a loss and am replying of someone who might have had a similar issue.

Any thoughts or insight would be greatly appreciated.

Thanks!

[JRL]

ETM
If it was OK before all that crap (you should not have used the other second cleaner), that probably messed it up
Takes a while, electronic

[kamiar]

Your car is a 2.4, the codes can still be read by DiCE and Vida even if the check engine light is off, it can be ETM or pedal sensor or other things.

[jderosa3]

When you say it messed up the ETM... Should I take it out and clean it? Or drive it a while until I can determine if it is actually bad (ei. This keeps happening.

I have a hard time beliveing the Lucas treatment could have caused this. I have been using it in my VW GTI Turbo for years without and ETM issue. Then again I have heard that the Volvo ETMs have had issues.

I have tried looking on IPDUSA for a part but cannot seem to find one. How much does the ETM cost for this car?

[jderosa3]

Your car is a 2.4, the codes can still be read by DiCE and Vida even if the check engine light is off, it can be ETM or pedal sensor or other things.

Hmmm... Ya... I only have a standard ODB-II scanner... that won't help.. .And these units cost upwards of 500 on Ebay... might be worth it to just take it to the dealer to get a scan and replace the parts myself.

Thoughts?

[Ars Gladius]

Don't know if this is of any help:

http://www.matthewsvolvosite.com/vol...module-fiasco/

[kamiar]

Hmmm... Ya... I only have a standard ODB-II scanner... that won't help.. .And these units cost upwards of 500 on Ebay... might be worth it to just take it to the dealer to get a scan and replace the parts myself.

Thoughts?

Even if it ETM that is faulty, it has 10 years extended warranty, but they will first charge you to clean it, if it didn't solve the problem, they will replace it under warranty.... check with your dealership with VIN number...

[jderosa3]

Kamiar,

Thanks for the info I will contact the dealer to see if it is covered. I believe it should be based on what I have read.

Just to add to this... I know that my generic CAN ODBII will not tell me what is wrong, but it did give me the following:

Freeze Frame:

Trouble Code: P1651

Fuel SYS1: OL, drive conditions
Fuel SYS2: NA

Calc Load (%): 69.8
Coolant (F): 178

St Firm1 (%): 0.0
Lt Firm1 (%): -24.2

Engine RPM: 2640
Vehicle Speed MPH: 43

Does this mean anything to you?

[kamiar]

Not good, though you have to get the car read by Vida, this is from Vida and it describes what exactly you experienced:


P1651 ECM-981A Engine control module (ECM). Internal fault Intermittent fault



284: ECM-981A Engine control module (ECM). Internal fault. Intermittent fault, B5254T2

Diagnostic trouble code (DTC) information ECM-981A

Condition
Diagnostic trouble code (DTC) ECM-981A is stored if the engine control module (ECM) registers an internal fault which indicates that the normal engine control functions are producing a higher torque than is within the maximum permitted range. The diagnostic trouble code (DTC) is diagnosed at ignition on or with the engine running.

Substitute value
The engine speed (RPM) is restricted to approximately 2200 rpm by shutting off the fuel.
The requested torque is limited to a calculated operating range.
Possible source
Defective engine control module (ECM).

Fault symptom[s]
Maximum engine speed (RPM) too low
Cruise control does not function at all
Uneven idle
Malfunction indicator lamp (MIL) lit.

[jderosa3]

So are you saying that the ECM is bad (possibly bad) and would need to be replaced? Or is there something physically wrong with the engine itself?

I know over the forums this is impossible to say - but I am going based on that code I gave you and the description of what you just sent me...

Also... Could the MAF just need cleaned? Based on this description below:

"ECM 981A = ECU internal fault , engine producing too much torque so limits engine power to 2200 rpm . so if it THINKS there is more air going in than is permitted therefore producing too much power it will shut down for safety."

Let me know your thoughts. I am a novice mechanic... Thanks!