bmw e90 320i limp mode diagnosis

bmdave · 05-22-2016, 02:29 AM

Hi all,
I have a problem where limp mode (big half engine light) comes on every few days and usually in the same spot on the way to work.
I have to pull over,switch off then on then im on my way.
Once it did come on and i could not reset for weeks.i swapped pedal for another from same model and did clear it.but 100m down street come back on.i then put old pedal back in and was fine for a few days till it happen again.
I have been to bmw and 3 differnt mechanics but no one can find the fault.
I did connect scan tool when it happen once and codes...
2d1a, 2d1b and 2d1c come up and were the only codes that come up which leads to accelerator pedal.
I was also advised to change throttle body which i have done but did not help the problem.
Any help would be much appreciated as i love this car so much.

Socket · 05-22-2016, 02:42 AM

Quote:

Originally Posted by demo

Hi all,
I have a problem where limp mode (big half engine light) comes on every few days and usually in the same spot on the way to work.
I have to pull over,switch off then on then im on my way.
Once it did come on and i could not reset for weeks.i swapped pedal for another from same model and did clear it.but 100m down street come back on.i then put old pedal back in and was fine for a few days till it happen again.
I have been to bmw and 3 differnt mechanics but no one can find the fault.
I did connect scan tool when it happen once and codes...
2d1a, 2d1b and 2d1c come up and were the only codes that come up which leads to accelerator pedal.
I was also advised to change throttle body which i have done but did not help the problem.
Any help would be much appreciated as i love this car so much.

Yes these codes are associated with the accelerator pedal signal

2D1A Accelerator Pedal Module
2D1B Accelerator Pedal Module Signal 1
2D1C Accelerator Pedal Module Signal 2

BMW yoda (Vtl) is the best person to help you understand this
Send him a private message (PM)

Fuji · 05-22-2016, 03:23 AM

Could be an issue with wiring leading to the pedal? Maybe check around for any damaged wires

:

bmdave · 05-22-2016, 04:01 AM

Sorry new to here,how do i search for him?
Yes they are the only codes that come up when i used a more advanced scan tool.
I did have a look at the plug a few times but wires look good and i cleaned with electrical cleaner but didnt do anything.
May be at ecu end but not sure.
Happened 3 times today,i tried unplugging then plugging back in while in limp mode but then accelerator pedal didnt work at all till i turned car off then on then cleared.

Fuji · 05-22-2016, 04:11 AM

@vtl you have been summoned

bmdave · 05-22-2016, 04:23 AM

Haha
Cheers mate.

vtl · 05-22-2016, 05:34 AM

I find code readers not that useful. A fault code has a lot of associated data that is more than just a code. Additional info might say that its an open circuit or intermittent etc. Really need INPA to get more detailed information, and would also be able to read what the computer thinks the pedal position is. Looked up the codes you posted and just indicates a throttle pedal issue, pretty vague.

If you've already replaced the pedal, it does point towards the harness for the pedal is most likely broken somewhere. You'd need to test the wires from the pedal to ECU. Sounds intermittent from what you've described.

But I'm still not convinced its still not a pedal problem cos it seemed to change once you replaced it. Need to swap the pedal over, then read the codes again if it comes back.

bmdave · 05-22-2016, 05:41 AM

When i did swap pedal over,the pedal was from a m sport 6cyl turbo model and mine is just the n46 4cyl.
Before swapping i did ask the euro wreckers if was the same between models because i wanted to test my friends pedal before purchasing.
But from what you are saying and i do agree...you are not convinced i should count out replacing pedal before going any further.
At $330 2nd hand you can see why i didnt want to buy before i knew 100% it was the cause of problem.

bmdave · 06-03-2016, 08:31 PM

Update!
Purchased pedal and went into limp mode 100m up the road so i am now pretty confident the problem is not the pedal.
I know this is a pretty random problem but any more ideas?

Fuji · 06-03-2016, 08:37 PM

Quote:

Originally Posted by demo

Update!
Purchased pedal and went into limp mode 100m up the road so i am now pretty confident the problem is not the pedal.
I know this is a pretty random problem but any more ideas?

Did you get the same codes? You'll need to consider properly inspecting/ potentially replacing the wiring to the pedal.

MR.BLUECOLLARMAN · 06-03-2016, 08:40 PM

Quote:

Originally Posted by demo

Update!
Purchased pedal and went into limp mode 100m up the road so i am now pretty confident the problem is not the pedal.
I know this is a pretty random problem but any more ideas?

Have you looked into other possible causes that might not be showing a code? Certain faults don't pop up when you scan the car, idk why honestly. Try taking a look at mechanical faults? Does the limp mode kick in when the car is cold/hot? Check VANOS solenoids/ESS (eccentric shaft sensor) I've heard they cause these kinds of issues.

bmdave · 06-03-2016, 08:50 PM

Do vanos dirty or malfunctioning vanos solanoids create a fault code?
Very frustrating problem this one as no one can really figure it out.
I have replaced throttle body and pedal now.
As for being hot or cold...
Today happened 5 minutes after starting in the morning.
But yesterday was fine untill about an hour of driving then i could not clear on side of road so had to drive in limp mode all the way home with lots of un happy people behind me.

MR.BLUECOLLARMAN · 06-03-2016, 08:52 PM

I know for sure the ESS doesn't show codes for some reason and you lose a lot of power but not sure if it kicks in limp mode. You can search it up online, I've seen a few DIY's. As for vanos you can blow them out with some compressed air and if that helps you can replace them as they will cause the same issue within a short period.

Fuji · 06-03-2016, 08:55 PM

Vanos solenoids will throw error codes if it's producing limp mode. The codes above don't indicate anything relating to vanos?

I'd be focusing on the cabling...

MR.BLUECOLLARMAN · 06-03-2016, 09:16 PM

Quote:

Originally Posted by Fuji

Vanos solenoids will throw error codes if it's producing limp mode. The codes above don't indicate anything relating to vanos?

I'd be focusing on the cabling...

Check the voltage going to the pedal before driving and then try to check it when limp mode kicks in. If the wiring/pedal are not faulty the DME may be faulty (rarely happens) that's why I was thinking something else was failing but not showing a code. What I would do is have the dealership/or someone you can find with ISTA/Rheingold drive around with you and right as it kicks into limp mode read the errors.

bmdave · 06-05-2016, 06:22 AM

Update!
Pulled vanos solanoids out and cleaned them.
Will report back the outcome after i drive car.
I will definatley try get to dealership while in limp.
A while back we did test voltage and run tests with scan tool and all were showing up fine.
Hope i can eventualy get to the vottom of this so i can pass it on to all so tgey dont go through what i have.
Also.
Is there anywhere i can find the exact wire colour or number of wires that are on the ecu end?
Would like to check the other end as pedal wirring is fine.

bmdave · 06-08-2016, 05:31 AM

Update!
2days and hasnt gone into limp mode yet.
Still looking for pin number of accelerator pedal on dme side and when i do i will check conections as i found 1 post that had similar problem and was a loose wire.
Appart from that post i couldnt find anything else relating to this problem aftwr months of searching.

Fuji · 06-08-2016, 06:00 AM

Quote:

Originally Posted by demo

Update!
2days and hasnt gone into limp mode yet.
Still looking for pin number of accelerator pedal on dme side and when i do i will check conections as i found 1 post that had similar problem and was a loose wire.

Nice! So you think the vanos solenoid cleaning resolved it? Seems to be completely unrelated! Haha

bmdave · 06-09-2016, 02:25 AM

Honestly NO...
Just waiting for it to go back into limp mode but trying to remain hopefull..
Haha...

Fuji · 06-09-2016, 05:44 AM

Quote:

Originally Posted by demo

Honestly NO...
Just waiting for it to go back into limp mode but trying to remain hopefull..
Haha...

So weird! Did you try anything else to remedy it?

Glad it's working for you somehow

MR.BLUECOLLARMAN · 06-09-2016, 05:50 AM

I'm not 100% sure but, doesn't the half engine symbol usually mean something mechanical? I had mine pop up when I disconnected the alternator, but when something electrical was disconnected it just gave me a check engine light.....ideas?

Socket · 06-09-2016, 06:18 AM

Quote:

Originally Posted by MR.BLUECOLLARMAN

I'm not 100% sure but, doesn't the half engine symbol usually mean something mechanical? I had mine pop up when I disconnected the alternator, but when something electrical was disconnected it just gave me a check engine light.....ideas?

Not always, could be a boost issue, electrical fault, almost anything that the car thinks can cause it harm, will trigger the dreaded half engine light. Usually if you restart the car at it goes away and doesn't return, then all is good

05-22-2016, 02:29 AM	#1
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	bmw e90 320i limp mode diagnosis Hi all, I have a problem where limp mode (big half engine light) comes on every few days and usually in the same spot on the way to work. I have to pull over,switch off then on then im on my way. Once it did come on and i could not reset for weeks.i swapped pedal for another from same model and did clear it.but 100m down street come back on.i then put old pedal back in and was fine for a few days till it happen again. I have been to bmw and 3 differnt mechanics but no one can find the fault. I did connect scan tool when it happen once and codes... 2d1a, 2d1b and 2d1c come up and were the only codes that come up which leads to accelerator pedal. I was also advised to change throttle body which i have done but did not help the problem. Any help would be much appreciated as i love this car so much.
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05-22-2016, 03:23 AM	#3
Fuji Lieutenant 98 Rep 577 Posts Drives: SGM E92 335i Join Date: Oct 2013 Location: Melbourne, Victoria iTrader: (0)	Could be an issue with wiring leading to the pedal? Maybe check around for any damaged wires : __________________ SGM E92 335i FBO [COLOR="Indigo"]/ MHD Stage 2 Plus / CP-E FMIC / DCI / VRSF DP / VRSF CP / Turbosmart Raceport BOV / BMW PE / H
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05-22-2016, 04:01 AM	#4
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	Sorry new to here,how do i search for him? Yes they are the only codes that come up when i used a more advanced scan tool. I did have a look at the plug a few times but wires look good and i cleaned with electrical cleaner but didnt do anything. May be at ecu end but not sure. Happened 3 times today,i tried unplugging then plugging back in while in limp mode but then accelerator pedal didnt work at all till i turned car off then on then cleared.
	Appreciate 0 Quote

05-22-2016, 04:11 AM	#5
Fuji Lieutenant 98 Rep 577 Posts Drives: SGM E92 335i Join Date: Oct 2013 Location: Melbourne, Victoria iTrader: (0)	@vtl you have been summoned __________________ SGM E92 335i FBO [COLOR="Indigo"]/ MHD Stage 2 Plus / CP-E FMIC / DCI / VRSF DP / VRSF CP / Turbosmart Raceport BOV / BMW PE / H
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05-22-2016, 04:23 AM	#6
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	Haha Cheers mate.
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05-22-2016, 05:34 AM	#7
vtl Brigadier General 1508 Rep 3,148 Posts Drives: 2008 BMW 135i MT Join Date: Apr 2015 Location: Melbourne, Australia iTrader: (0)	I find code readers not that useful. A fault code has a lot of associated data that is more than just a code. Additional info might say that its an open circuit or intermittent etc. Really need INPA to get more detailed information, and would also be able to read what the computer thinks the pedal position is. Looked up the codes you posted and just indicates a throttle pedal issue, pretty vague. If you've already replaced the pedal, it does point towards the harness for the pedal is most likely broken somewhere. You'd need to test the wires from the pedal to ECU. Sounds intermittent from what you've described. But I'm still not convinced its still not a pedal problem cos it seemed to change once you replaced it. Need to swap the pedal over, then read the codes again if it comes back. __________________ Build Thread
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05-22-2016, 05:41 AM	#8
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	When i did swap pedal over,the pedal was from a m sport 6cyl turbo model and mine is just the n46 4cyl. Before swapping i did ask the euro wreckers if was the same between models because i wanted to test my friends pedal before purchasing. But from what you are saying and i do agree...you are not convinced i should count out replacing pedal before going any further. At $330 2nd hand you can see why i didnt want to buy before i knew 100% it was the cause of problem.
	Appreciate 0 Quote

06-03-2016, 08:31 PM	#9
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	Update! Purchased pedal and went into limp mode 100m up the road so i am now pretty confident the problem is not the pedal. I know this is a pretty random problem but any more ideas?
	Appreciate 0 Quote

06-03-2016, 08:50 PM	#12
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	Do vanos dirty or malfunctioning vanos solanoids create a fault code? Very frustrating problem this one as no one can really figure it out. I have replaced throttle body and pedal now. As for being hot or cold... Today happened 5 minutes after starting in the morning. But yesterday was fine untill about an hour of driving then i could not clear on side of road so had to drive in limp mode all the way home with lots of un happy people behind me.
	Appreciate 0 Quote

06-03-2016, 08:52 PM	#13
MR.BLUECOLLARMAN Second Lieutenant 48 Rep 270 Posts Drives: E90 06 325i Sedan Silver Join Date: Dec 2015 Location: South Carolina iTrader: (0)	I know for sure the ESS doesn't show codes for some reason and you lose a lot of power but not sure if it kicks in limp mode. You can search it up online, I've seen a few DIY's. As for vanos you can blow them out with some compressed air and if that helps you can replace them as they will cause the same issue within a short period.
	Appreciate 0 Quote

06-03-2016, 08:55 PM	#14
Fuji Lieutenant 98 Rep 577 Posts Drives: SGM E92 335i Join Date: Oct 2013 Location: Melbourne, Victoria iTrader: (0)	Vanos solenoids will throw error codes if it's producing limp mode. The codes above don't indicate anything relating to vanos? I'd be focusing on the cabling... __________________ SGM E92 335i FBO [COLOR="Indigo"]/ MHD Stage 2 Plus / CP-E FMIC / DCI / VRSF DP / VRSF CP / Turbosmart Raceport BOV / BMW PE / H
	Appreciate 0 Quote

06-05-2016, 06:22 AM	#16
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	Update! Pulled vanos solanoids out and cleaned them. Will report back the outcome after i drive car. I will definatley try get to dealership while in limp. A while back we did test voltage and run tests with scan tool and all were showing up fine. Hope i can eventualy get to the vottom of this so i can pass it on to all so tgey dont go through what i have. Also. Is there anywhere i can find the exact wire colour or number of wires that are on the ecu end? Would like to check the other end as pedal wirring is fine.
	Appreciate 0 Quote

06-08-2016, 05:31 AM	#17
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	Update! 2days and hasnt gone into limp mode yet. Still looking for pin number of accelerator pedal on dme side and when i do i will check conections as i found 1 post that had similar problem and was a loose wire. Appart from that post i couldnt find anything else relating to this problem aftwr months of searching.
	Appreciate 0 Quote

06-09-2016, 02:25 AM	#19
bmdave New Member 7 Rep 16 Posts Drives: bmw e90 320i Join Date: May 2016 Location: australia iTrader: (0)	Honestly NO... Just waiting for it to go back into limp mode but trying to remain hopefull.. Haha...
	Appreciate 0 Quote

06-09-2016, 05:50 AM	#21
MR.BLUECOLLARMAN Second Lieutenant 48 Rep 270 Posts Drives: E90 06 325i Sedan Silver Join Date: Dec 2015 Location: South Carolina iTrader: (0)	I'm not 100% sure but, doesn't the half engine symbol usually mean something mechanical? I had mine pop up when I disconnected the alternator, but when something electrical was disconnected it just gave me a check engine light.....ideas?
	Appreciate 0 Quote