On these older Volts with this type of problem it’s recommended to always use Mountain Mode to maintain that 3-4 bars of indicated charge in the guessometer. Also most older Volts are now very temperature reactive. For example my 2011 will perform basically fine per expectations (obviously showing it’s age with some degradation) at temps above 45ish so a great summer car, but at temps closer to 32-45 the ICE will run most of the time. And yes sometimes the ICE will scream with high revs. Reduced propulsion is rare for mine but then again I’m rarely on the freeway with it. Does yours behave better on 40ish mph surface streets as opposed to freeway? What you describe sounds like some version of the weak cell in the HV battery. When software sees a weak cell it fires up ICE to get some charge going into the weak cell.
2011 with P16E0 and P0AC4 and propulsion power reduced
I've had two related issues for about a month now with our 2011 Chevy Volt.
Issue 1: The situation is that when the ICE kicks on after the electric range in either normal or mountain mode goes to zero, the engine seems to struggle to produce adequate power to keep the batteries sufficiently charged and maintain speed. At highway speeds (say 65mph+) the engine will start to over rev (probably 1500 higher than the normal high range of engine) in an attempt to produce more power. After a few seconds at this unusually high RPM range, a "Propulsion Power is Reduced" message appears. At this point, the car will continue to rev very high even if the speed is reduced to 25-30mph. If the car is parked and the battery is allowed to charge for several minutes, the messages go away and the car will drive normally at speeds below 65mph.
The DTC codes associated with this event are always P16E0 and P0AC4. I've also occasionally gotten a P0101 (MAF sensor) if I continue to push the engine a little longer, but I think that's a secondary result caused by the engine over revving and not the underlying issue.
Issue 2: Around the same time the above issue started, the MPG in ICE mode suddenly plummeted from 35-40 to 25-30.
P16E0 is "no torque detected," but clearly the engine is still producing some power, just not all of it is getting to the battery or the wheels. I've only found a few references to the P16E0 code and no solutions. Given the issues I'm experiencing, I'm suspecting it could be something to do with clutch 2 in the "1st generation" diagram on the attached link.
www.gm-volt.com
If there was an issue with clutch 2, the engine would still be capable of producing 55kw via motor A to charge the battery, but wouldn't be able to connect to the planetary gear and therefore not be able to recharge the battery using the 111kw from motor B. This would seem to explain the lack of power and mpg even when the engine seems to running normally (not loud, rough, or excessive exhaust) with no codes presenting.
Does this make sense to anyone or fit an issue you may have experienced? If it is the clutch, shouldn't I get code for that like P079B?
I've already replaced the 12v battery, replaced the spark plugs, swapped the MAF sensor, and had the dealership update the hybrid control module software. I asked dealership to look at this issue, but something got lost in communication and it later became clear that they had no clue where to begin, so I just brought it home. It runs fine in electric mode and still runs fine below 65 mph (albeit with the terrible 25-30 mpg) so a transmission replacement seems silly, but I'd still like to understand the issue. Any thoughts are greatly appreciated.
Issue 1: The situation is that when the ICE kicks on after the electric range in either normal or mountain mode goes to zero, the engine seems to struggle to produce adequate power to keep the batteries sufficiently charged and maintain speed. At highway speeds (say 65mph+) the engine will start to over rev (probably 1500 higher than the normal high range of engine) in an attempt to produce more power. After a few seconds at this unusually high RPM range, a "Propulsion Power is Reduced" message appears. At this point, the car will continue to rev very high even if the speed is reduced to 25-30mph. If the car is parked and the battery is allowed to charge for several minutes, the messages go away and the car will drive normally at speeds below 65mph.
The DTC codes associated with this event are always P16E0 and P0AC4. I've also occasionally gotten a P0101 (MAF sensor) if I continue to push the engine a little longer, but I think that's a secondary result caused by the engine over revving and not the underlying issue.
Issue 2: Around the same time the above issue started, the MPG in ICE mode suddenly plummeted from 35-40 to 25-30.
P16E0 is "no torque detected," but clearly the engine is still producing some power, just not all of it is getting to the battery or the wheels. I've only found a few references to the P16E0 code and no solutions. Given the issues I'm experiencing, I'm suspecting it could be something to do with clutch 2 in the "1st generation" diagram on the attached link.
Gen 2 Volt Transmission Operating Modes Explained
By Jeff N, Patrick Groeneveld and George Bower Preface This article is based on a GM patent US 8,602,938 , issued in December 2013, and presentations by GM at an SAE vehicle electrification conference on February 11, 2015 in Los Angeles. The presentations by GM verify that the patent...
www.gm-volt.com
If there was an issue with clutch 2, the engine would still be capable of producing 55kw via motor A to charge the battery, but wouldn't be able to connect to the planetary gear and therefore not be able to recharge the battery using the 111kw from motor B. This would seem to explain the lack of power and mpg even when the engine seems to running normally (not loud, rough, or excessive exhaust) with no codes presenting.
Does this make sense to anyone or fit an issue you may have experienced? If it is the clutch, shouldn't I get code for that like P079B?
I've already replaced the 12v battery, replaced the spark plugs, swapped the MAF sensor, and had the dealership update the hybrid control module software. I asked dealership to look at this issue, but something got lost in communication and it later became clear that they had no clue where to begin, so I just brought it home. It runs fine in electric mode and still runs fine below 65 mph (albeit with the terrible 25-30 mpg) so a transmission replacement seems silly, but I'd still like to understand the issue. Any thoughts are greatly appreciated.
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Let's open one important nut first: The Volt starts weird. It has a 55kw, 300v starter motor. If it's trying to start, and fails, it will SOUND exactly like it's started because that starter motor normally spins that engine up tooperating RPM, then adds spark and gas. And it will keep doing that for a rather long time if it needs to. This adds a lot of complication in that it's really hard to tell if the engine actually has started or is merely being cranked.
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The other code in concert that doesn't relate to fuel injector control voltages is
P0AB9: shows up when engine is being cranked, and the speed didn't rise above the speed it's being cranked at, which is one way the car knows that the engine has actually started. It also pops up when the engine stalls. This is based on engine RPM
P16E0: That's the No Torque one: It sets under basically any condition where the engine has failed to start or stalls due to any of the normal three failures of engines: No spark, no air, no fuel. This is based on monitoring from the HPCM, which (I think) means it's not seeing juice coming out of the generator when it's expecting to.
P0AC4: Informational DTC. It sets when the Hybrid Powertrain Control Module has sent a emissions-related message. The emissions-related message could be "Hey, there's something weird happening with engine..." That is, it's supposational but logical that sending the P16E0 also sets P0AC4.
The common theme to both of these paths is that they're saying the engine ain't running, it's just cranking. You've said it eventually charges the battery enough to settle down, so it is eventually actually starting (probably when it starts revving up), but it's taking longer than it should, and the high-revving for a while after is common to a very deep discharge into The Bad Place chargewise, and the generator hurrying to get the voltage back up, possibly while still having to move the car. Which is consistent with the engine taking longer than it should to actually start.
Now WHY it might be taking longer is something I don't have enough information to guess at.
Both codes show up in concert here:I've had two related issues for about a month now with our 2011 Chevy Volt.
Issue 1: The situation is that when the ICE kicks on after the electric range in either normal or mountain mode goes to zero, the engine seems to struggle to produce adequate power to keep the batteries sufficiently charged and maintain speed. At highway speeds (say 65mph+) the engine will start to over rev (probably 1500 higher than the normal high range of engine) in an attempt to produce more power. After a few seconds at this unusually high RPM range, a "Propulsion Power is Reduced" message appears. At this point, the car will continue to rev very high even if the speed is reduced to 25-30mph. If the car is parked and the battery is allowed to charge for several minutes, the messages go away and the car will drive normally at speeds below 65mph.
The DTC codes associated with this event are always P16E0 and P0AC4. I've also occasionally gotten a P0101 (MAF sensor) if I continue to push the engine a little longer, but I think that's a secondary result caused by the engine over revving and not the underlying issue.
Issue 2: Around the same time the above issue started, the MPG in ICE mode suddenly plummeted from 35-40 to 25-30.
P16E0 is "no torque detected," but clearly the engine is still producing some power, just not all of it is getting to the battery or the wheels. I've only found a few references to the P16E0 code and no solutions. Given the issues I'm experiencing, I'm suspecting it could be something to do with clutch 2 in the "1st generation" diagram on the attached link.
Gen 2 Volt Transmission Operating Modes Explained
By Jeff N, Patrick Groeneveld and George Bower Preface This article is based on a GM patent US 8,602,938 , issued in December 2013, and presentations by GM at an SAE vehicle electrification conference on February 11, 2015 in Los Angeles. The presentations by GM verify that the patent...
If there was an issue with clutch 2, the engine would still be capable of producing 55kw via motor A to charge the battery, but wouldn't be able to connect to the planetary gear and therefore not be able to recharge the battery using the 111kw from motor B. This would seem to explain the lack of power and mpg even when the engine seems to running normally (not loud, rough, or excessive exhaust) with no codes presenting.
The other code in concert that doesn't relate to fuel injector control voltages is
P0AB9: shows up when engine is being cranked, and the speed didn't rise above the speed it's being cranked at, which is one way the car knows that the engine has actually started. It also pops up when the engine stalls. This is based on engine RPM
P16E0: That's the No Torque one: It sets under basically any condition where the engine has failed to start or stalls due to any of the normal three failures of engines: No spark, no air, no fuel. This is based on monitoring from the HPCM, which (I think) means it's not seeing juice coming out of the generator when it's expecting to.
P0AC4: Informational DTC. It sets when the Hybrid Powertrain Control Module has sent a emissions-related message. The emissions-related message could be "Hey, there's something weird happening with engine..." That is, it's supposational but logical that sending the P16E0 also sets P0AC4.
The common theme to both of these paths is that they're saying the engine ain't running, it's just cranking. You've said it eventually charges the battery enough to settle down, so it is eventually actually starting (probably when it starts revving up), but it's taking longer than it should, and the high-revving for a while after is common to a very deep discharge into The Bad Place chargewise, and the generator hurrying to get the voltage back up, possibly while still having to move the car. Which is consistent with the engine taking longer than it should to actually start.
Now WHY it might be taking longer is something I don't have enough information to guess at.
1 - 20 of 23 Posts
