All Yellow - EML, Traction and Brake Lights ON! then "Limp Mode"

[1MrLuis]

Hello All,
this is my first post so I will give as much detail as possible. First off, thank you to all who post here. It has been a very informative way to get to know my car.
I purchased a 2004 325i automatic (M54 engine) about a year and a half ago (Feb 2015). I have performed several maintenance fixes. A few weeks back I had a local shop replace the oil pan gasket to fix an oil leak. A couple of days later about a mile from home the EML, Traction and Brake lights (All Yellow) came on and the car went into limp mode. I chugged home since I was too scared to turn the car off. The next day, started the car and drove fine for about 8 miles. Issue happened again. Pulled over turned off and restarted the car and turned around and drove home. Began the research to find an answer to my car's issues.
Found several threads leading to the Throttle Position Sensor. I called around and was told by several people including my local BMW dealer that this car's Throttle Position Sensor is located in the Accelerator Pedal unit. I ordered a new pedal assembly and new intake boots. I have replaced these parts and went for a test drive. When I punched the gas pedal, the car made a low bellowing sound then slowing picked up speed. Shifted well. When the RPM's got to about 4000 the lights came on again and the car went into Limp Mode again.
Before you ask me for codes - I don't have codes to provide. I got an OBD2 scanner from AutoZone however, it didn't pull codes. I have ordered an iCarsoft i910 diagnostics tool but it hasn't arrived yet.
I am hoping someone has had a similar issue and could share your experiences. Also, if there are other TPS's on my car please let me know where they are located. Most of the posts that show a top TPS are M3 models and as I stated, mine is not.

Appreciate any help!
Luis B.

[MIKYZZ4]

How old is the battery? Check battery- if possible- remove from car- hook it up to a battery charger until 100% full charge- have it load tested at local AutoZone. If it doesn't hold a voltage of 12.4~12.7, replace.

[1MrLuis]

Thank you Mikyzz4 for your reply to my post. I actually had the battery tested the day after this "issue" appeared. The guys at AutoZone said the battery was good. I don't know how old it is, but after receiving your reply I got home and put my volt meter to the battery. It tested at 12.2V. I am going to Batteries Plus to have them check it out then I am going to Advance Auto parts to have them test again. This has been a very puzzling issue but if it turns out to be the battery, I will be very happy. Then onto the next project.
Thank you again.

[MIKYZZ4]

Check and clean your wheel speed sensors, as that is known to cause the trifecta of lights on dash.

[1MrLuis]

Check and clean your wheel speed sensors, as that is known to cause the trifecta of lights on dash.

Thank you, I will do that as well. I do however can't understand how the wheel sensors would cause the engine to have a "bellowing" sound when I depress hard the accelerator. This happens at 2k RPM and has a slight stall, then accelerates and shifts well until 4k RPM when it goes into 'Limp' mode with Trifecta lights.

Thanks again,
Luis

[MIKYZZ4]

Do you have an automatic trans?

- - - Updated - - -

Sorry, I didn't notice that in your first post. You need to clear codes and re-scan with BMW specific scanner or a computer with BMW software. You may need an update to transmission module that only BMW can provide, but let's stay optimistic and work with what you have. Re-scan when the iCarSoft tool arrives.

[1MrLuis]

Do you have an automatic trans?

- - - Updated - - -

Sorry, I didn't notice that in your first post. You need to clear codes and re-scan with BMW specific scanner or a computer with BMW software. You may need an update to transmission module that only BMW can provide, but let's stay optimistic and work with what you have. Re-scan when the iCarSoft tool arrives.

Yes, I am still waiting on scanner. I thought it would be here by now (today) but not yet. Just got back from having battery tested. All good there. So back to square 1.
Waiting for scanner and we'll go from there.
Thanks again.

[xLukas]

Any fix? This is extremely annoying on my car.

My transmission has been updated, so this update cannot be my issue.
Limp mode sucks.


Update: this isnt an actual repair, but a possible short term solution. I'm sitting in my car on my break at work. Had the key in ignition and I know it'll have the limp mode issue if the lights are illuminated before start up. I reset the transmission by putting my key in ignition to position one, holding the accelerator down for 10 seconds and the lights were gone and no limp mode.

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[All2kool]

I've had this trifecta of lights three times myself but each time, the car was running fine, continued to run fine to my destination, and the lights were not present on restart. The first time there were no codes, the next two times a 'P1500 - Idle Control Valve Stuck Open'. After the first P1500, I removed and thoroughly cleaned the ICV but it happened again. As soon as the weather permits, I plan on changing the ICV Rubber Boot and the ICV itself as both I believe are original to the car (135K miles).

I have concluded that the trifecta of lights will not always trigger limp mode, which is good I guess.

[1MrLuis]

Hello xLukas,
I fixed my car. It turned out to be bad "Cats". Exhaust was so bad that it was backing up the engine thus causing the 'Trifecta'.

Hope this helps you.

[xLukas]

Hello xLukas,
I fixed my car. It turned out to be bad "Cats". Exhaust was so bad that it was backing up the engine thus causing the 'Trifecta'.

Hope this helps you.

I have had a P0420 which is catalyst efficiency below threshold for a while. However I just though it was a bad O2 sensor because of no telltale signs of bad cats.. huh

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[1MrLuis]

My iSoft scanner didn't pull any codes. But in talking to a friend, we figured it best to check the exhaust and sure enough that was it. The car was not exhausting powerfully. Seemed weak. And that is what it was. You may want to take to a muffler shop..??

[xLukas]

My iSoft scanner didn't pull any codes. But in talking to a friend, we figured it best to check the exhaust and sure enough that was it. The car was not exhausting powerfully. Seemed weak. And that is what it was. You may want to take to a muffler shop..??

I should get a laser thermometer to see if the cat is actually bad, or like you said take it to an exhaust shop. Thanks for the heads up

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[All2kool]

I have had a P0420 which is catalyst efficiency below threshold for a while. However I just though it was a bad O2 sensor because of no telltale signs of bad cats.. huh

Don't know if this is of any help but I had the P0420 on my 1996 Lincoln Town Car. Turned out to be fouled Plug Wire causing an intermittent connection. I had taken the car to Meineke for a diagnosis and they wanted to sell me a $130 'Fuel System Cleaning'. I said thanks but no. I then discovered the fouled Plug Wire and when I asked Meineke how a 'Fuel System Cleaning' would have corrected that, they were silent.

If I were you, I would check each Coil for corrosion.

Of course, I could be completely off base here and I'm sure one of the veterans here will be quick to point that out.

[MIKYZZ4]

I have had a P0420 which is catalyst efficiency below threshold for a while. However I just though it was a bad O2 sensor because of no telltale signs of bad cats.. huh

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Have an exhaust backpressure test performed.
Are any other codes being displayed?

[xLukas]

Have an exhaust backpressure test performed.
Are any other codes being displayed?

No other codes. Just a P0420 consistently.

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[MIKYZZ4]

Possibly failed cat. Pressure test can verify if cat clogged or obstructed.
O2 sensors can be changed, as they are a recommended maintenance item with 100k service life.

[xLukas]

Possibly failed cat. Pressure test can verify if cat clogged or obstructed.
O2 sensors can be changed, as they are a recommended maintenance item with 100k service life.

I think I may order a laser thermometer to check temp front and rear of each cat. If one end is much hotter that means it's clogged. Thanks for all the help guys.

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[All2kool]

Possibly failed cat. Pressure test can verify if cat clogged or obstructed. O2 sensors can be changed, as they are a recommended maintenance item with 100k service life.

This is what I thought as well when it happened on my Town Car. I watched a YouTube video that suggested a gallon of lacquer thinner to a full tank of gas could clean a catalytic converter. I tried it but as I posted earlier, my P0420 was from a rusted and fouled plug wire not making good contact to a spark plug. I verified this by moving the plug wire from the cylinder misfire was also occurring to another cylinder. The problem followed the plug wire so I knew what was wrong.