SUCCESS!! OM642 320CDI CEL, limp mode, codes p0111-p1111-p1100-p0100, P0489, P0245, P2009

(Spoiler Alert! It was the Swirl Motor and I fixed it with the "resistor mod" and I've outlined that information in post #2)

Background:
2008 GL320CDI, 108K miles, purchased at 98K miles and it's run flawlessly for the last
I'm making this post to catch in people's searches and hopefully provide options and answers to others with these common problems.

This is my first Mercedes, although it replaced a 1994 Saab 9000 Aero 5MT that I purchased with 140K miles and sold 11yrs later with 300K miles - doing the majority of the work myself. I figured if I could keep a Saab on the road a Mercedes would be a snap. I've been mostly correct.

Just after this Chinese Covid thing hit (Mar31) the truck went into limp mode on the freeway without warning. The CEL came on at the first stop and there was no acceleration power in any gear.

I used a $99 bluetooth OBD tool called .


It gave the following codes:
P1111 - Atmospheric Pressure Sensor High Input
P1100 - Starter Switch Circuit (off) - OR (Left MAF sensor) (later found this might reference a Fault detected during DPF regeneration)
P0489 EGR "A" Control Circuit Low
P0111 - IAT - Intake Air Temp Sensor 1 Circuit Range Bank 1
P0100 - Mass Air Flow Sensor "A" circuit (later found out PO100 is circuit MAF)
P2009 - Intake Manifold Runner - Low Bank 1
P0245 - Wastegate Solenoid "A" Low

(NOTE: After a few weeks of frustrations with obscure OBD trouble codes that don't translate directly to a MB trouble codes, I broke down and purchased a $150 iCarsoft MBII scanner that connects via cable. I can't say I'm elated with the purchase, but it was bittersweet. It pulls the SAME OBD codes (partially because that's the entire purpose of OBD), but doesn't seem to translate them into a Mercedes specific code. I can't say that this expense was helpful in solving this specific CEL problem I was having - although that could be more a factor of my competence than a mark on the ability of the scanner - however, I may end up keeping it in the truck for future needs. In the end, the iCarsoft MBII produced no different results than my BlueDriver bluetooth scanner that resulted in solving this problem. Moral: don't be so quick to buy an expensive scanner)


More online research led me to other posts with the same codes:
https://www.benzworld.org/threads/ce.../#post-5552574

https://www.benzworld.org/threads/r3.../#post-5067111

https://www.benzworld.org/threads/20...#post-12297409 - SOLUTION - Inlet Port Shutoff Motor

https://mbworld.org/forums/gl-class-...de-320cdi.html

https://www.benzworld.org/threads/r3...-help.1658191/



For some reason, my initial research returned posts that led me to the wastegate actuator. Sadly, I think I fell victim to the Shoot, Ready, Aim style of troubleshooting in this case. Posts from 2010 said you had to buy the turbo/actuator together at a cost of $4K. Posts starting in 2017 were showing that it was a circuit inside the actuator that fractures and causes the failure AND that it could be removed and patched. Well, damn, this is right up my alley. But I ended up breaking the circuit more during repair, so I had to purchase a replacement or $130. My excitement was boundless as I went for my first test drive after the repair. I was already theorizing how wonderful the boost would be. Sadly, the truck was unchanged. Sluggish, CEL lit, limp mode evident from the first press of the accelerator. Back to the drawing board.

Here is my list of work / parts / repairs over the course of Covid:

APR1 to MAY25 work history

• Remove + attempt to repair Wastegate Actuator
• Replaced Wastegate actuator $140
• Replace fuel filter $60
• Replace air filters $35 (DO I REALLY need to visit the dealer to reset the ECU?!)
• Removed / cleaned EGR valve with Easy-Off oven cleaner
• Checked Boost hoses for leaks/cracks
• Test drive with/without MAF plugged in
• Inspect and replace Fuse #104 (blown)
• Replace DPF pressure sensor $80
• Purchase iCarsoft MBII $150
• Resistor mod plugged into Swirl Motor harness $5
• Clean DPF with Liqui-moly treatment - $70 + home built garden sprayer
• Spray Clean MAF with CRC MAF cleaner $8 (MAY25 - I'm on the edge of throwing in the towel and taking the car to a shop)
• Inspect fuse #104 (and others)
• Inspect / re-adjust the MAF tube + gaskets
• Inspect/ re-adjust air filter box connections
• Double-check resistor on swirl motor

Now, that's a major list of parts that didn't necessarily need to be touched. But keep in mind, this was a new-to-me truck that already had 98K miles when purchased. I'm sure some of those fell into the normal maintenance schedule, so I feel good about having done the research and completed the work. The most difficult part of the project was removing and cleaning the EGR valve. That's not to say that was a difficult job, it was just arduous, moreso than the solution - which was literally plugging two ends of a resistor into the body harness.


So, in the interest of clarity, I'm putting the SOLUTION that worked for me in Post #2. If you're reading this, hopefully something in this process will work to get your CDI back into service for minimal cost.

 

OM642 320CDI CEL, limp mode, codes p0111-p1111-p1100-p0100, P0489, P0245, P2009


SOLUTION - Defective Swirl Motor. Use a 4K7 Ohm (4.7K) 0.25W resistor The resistor is connected to the live and signal wires which are red/green and grey on the crd, these are actually the two centre connections on the plug, it is a four pin plug with three wires.

This user has the same list of codes back in 2012
https://mbworld.org/forums/gl-class-...de-320cdi.html
Then he installed a resistor on the servo motor to get the swirl motor working again.
https://www.jeepforum.com/forum/f67/...r-mod-1397852/

I thought I purchased a 10-pack of the resistors from eBay for $5. Turns out it was a 10-pack of 10-packs so now I have an extra 99 resistors. I'm thinking of making some direct plug harnesses and selling them for $5 shipped just so I don't feel guilty for wasting 99 of them.

 

Thanks for taking the time to share your experience. I'm sure it will benefit others.

Just a word of caution for anyone who has a '10-'12 model. MB added intake runner position sensors so going the resistor route will fix the CEL caused by the bad swirl flap motor, but will cause P2004 and P2005:intake runner stuck open bank 1 & 2. I took the swirl motor out on mine while doing the oil cooler job and just had to struggle to reinstall and connect the swirl flap motor without removing the intakes. Massive PIA of my own making for not knowing about the intake runner position sensors.

 

Brilliant! Just found this and it's exactly the same set of error codes I've had for a while and not been able to solve. I've just purchased a bypass emulator from ebay so fingers crossed that will work! I'll let you know....

 

Excellent! Hope it all turns out for you.

In a funny twist, I just threw out the remaining 99 resistors two weeks ago. My truck is still running strong. Just turned 140K miles.

 

Sorry I forgot to post an update. Replaced MAF sensor pipe and put in emulator. CEL stayed on at first, but after about 20 restarts, the light was gone and car is flying! Thanks so much.