Still on limp home mode after ETA and MAF replacement

[zx10r]

I'm stumped and I hope someone can help
I purchased a rebuilt ETA from Don at RFC electronics, purchased a used MAF via EBAY 2x
Cleared all the codes on both MAFand yet it still won't get past 35mph
Am I missing something? Suggestions?

 

[gerryvz]

Have you pulled codes to see what is being indicated? Then reset, drive the car for 50 miles or so, then pull codes again?

What codes have you gotten in the past?

 

[gsxr]

Need lots more info. What is the exact problem? Misfire? Poor throttle response? Low power? Runs great below 35mph but won't go any faster? Will it rev to redline in 1st gear? Etc.

Checking / clearing codes will help too. If there are no codes, that narrows down the possibilities. If there are codes, what are they, from each of the 6 powertrain modules?

 

[Eno]

The reference “limp mode” actually may be wrong wording IMO.
In my country they call it “emergency phase” when ASR is suddenly lit or ON and loss of power with a non-responsive ETA.
Check the electronic switch (photo attached) behind the gas pedal and check the codes.
Also clean/check the ASR cable on top of the differential.
Also check/clean/replace the ABS sensor which may give an intermittent fault that’s why the car goes in an “emergency phase” or as you guys in The States call it “limp mode”.
This is a safety mechanism if I am not mistaken.

 

[zx10r]

Have you pulled codes to see what is being indicated? Then reset, drive the car for 50 miles or so, then pull codes again?

What codes have you gotten in the past?

The codes that came out were:
pin 6 code 30 CAN data line to electronic accelerator,
pin7-6 back up lamp,
pin7-14 closed throttle position contact switch,
pin19-6 idle speed control faulty
pin19-10 voltage at mass air too high/low

 

[zx10r]

Need lots more info. What is the exact problem? Misfire? Poor throttle response? Low power? Runs great below 35mph but won't go any faster? Will it rev to redline in 1st gear? Etc.

Checking / clearing codes will help too. If there are no codes, that narrows down the possibilities. If there are codes, what are they, from each of the 6 powertrain modules?

My problem is the car runs great below 35mph but won't go any faster
When it gets up to 35, it feels like it wants to go faster but it won't, no stalling or anything like that
When in Park, I can rev the engine up to redline

I've only pulled codes from the 38 pin and not sure how to get any other codes from the 6 powertrain modules
No check engine light signs, ASR light signs come up during driving

I did clear all the codes prior to starting the car multiple times but still come up with not going faster than 35 mph

 

[gsxr]

My problem is the car runs great below 35mph but won't go any faster
When it gets up to 35, it feels like it wants to go faster but it won't, no stalling or anything like that

Is there full power to 35mph, i.e. does it rocket to 35mph then just won't go faster? Or does power taper off as you near 35mph?

When in Park, I can rev the engine up to redline

That is not normal. Likely related to pin 7 code 6, the NSS on the transmission.

I've only pulled codes from the 38 pin and not sure how to get any other codes from the 6 powertrain modules

You access all 6 modules from the 38-pin socket. Use the DTC list PDF file in this post to translate the codes:

FYI - HOW-TO: Checking DTC's (Diagnostic Trouble Codes) on the 500E/E500 | De-Coding

UPDATE: To buy a pre-built code reader, click here (NLA by 2023) or click here (still available in 2023) for an affordable one from eBay. If you do not have a "breakout box", make sure you select the type of reader with the small 1mm pins, i.e. for 400E, not the type with the large 4mm pins. A...

www.500eboard.co

No check engine light signs, ASR light signs come up during driving

That just means there are no emissions related faults (CEL), and no limp mode (ASR light).

I did clear all the codes prior to starting the car multiple times but still come up with not going faster than 35 mph

Which codes come back after you clear them? Those are the ones you need to fix.


Anyway - if power tapers off, and/or you don't have full power below 35mph, you may have either restricted fuel supply or plugged catalysts. Those would be separate from fixing the problems which are causing the fault codes.

:

 

[zx10r]

Is there full power to 35mph, i.e. does it rocket to 35mph then just won't go faster? Or does power taper off as you near 35mph?

- It feels as though it rockets to 35 but once it hits 30 it does taper off and feels sluggish and stays at 35.

That is not normal. Likely related to pin 7 code 6, the NSS on the transmission.

- I have ordered a OEM brake switch for $24 and will swap out. Will this help with this issue? It often comes up

Which codes come back after you clear them? Those are the ones you need to fix.

-Most often Pin 7 Code 6, sporadically Pin 19 Code 10

Anyway - if power tapers off, and/or you don't have full power below 35mph, you may have either restricted fuel supply or plugged catalysts. Those would be separate from fixing the problems which are causing the fault codes.

- Would cap and rotor, spark plug and fuel filter change help? The car runs fine but its been a few years since I've performed this.
-Is there a way to check for a plugged catalyst?

 

[gsxr]

- It feels as though it rockets to 35 but once it hits 30 it does taper off and feels sluggish and stays at 35.

That is WEIRD.

I have ordered a OEM brake switch for $24 and will swap out. Will this help with this issue? It often comes up

The brake light switch is cheap and easy to replace, and a semi-common failure, but none of your fault codes indicate this is an issue. And, it would cause limp mode (or ASR light on), not a power loss.

Most often Pin 7 Code 6, sporadically Pin 19 Code 10

This is the NSS (Neutral Safety Switch, aka Starter Lockout / Backup Light switch), S16/1. This is a VERY common failure. It's expensive and a minor nuisance to replace, but you need to do it. However I don't think it's causing the 35mph roadblock.

Would cap and rotor, spark plug and fuel filter change help? The car runs fine but its been a few years since I've performed this.

Most likely this would be a waste of money. Fix the fault codes first.

Is there a way to check for a plugged catalyst?

Remove the crossover pipe from driver manifold, to the main pipe on the passenger side. It will be loud, but test drive with the pipe removed. If no change, it's not plugged cats. More scientifically you can remove the O2 sensor, install an exhaust pressure gauge that reads 0-5psi, and test drive at WOT. This is a lot more work and requires buying a gauge.

pin 6 code 30 CAN data line to electronic accelerator,
pin7-6 back up lamp,
pin7-14 closed throttle position contact switch,
pin19-6 idle speed control faulty
pin19-10 voltage at mass air too high/low

I missed one of those faults, ooops:

pin 6 code 30 CAN data line to electronic accelerator - This is a "ghost code" that usually appears with pin 7 code 6.
pin7-6 back up lamp - NSS S16/1 on transmission, you should replace this, it MUST be adjusted properly during installation
pin7-14 closed throttle position contact switch - This is S29/3 at the gas pedal, may need replacement
pin19-6 idle speed control faulty - Possibly related to the codes above

pin19-10 voltage at mass air too high/low <-- THIS could be the cause of your 35mph issue. Try disconnecting the MAF, twist the round connector ring to unlock/remove it. Test drive the car. If the problem is cured, your MAF is probably defective and needs replacement.

 

[zx10r]

pin19-10 voltage at mass air too high/low <-- THIS could be the cause of your 35mph issue. Try disconnecting the MAF, twist the round connector ring to unlock/remove it. Test drive the car. If the problem is cured, your MAF is probably defective and needs replacement.

- I did that, I unplugged the pancake socket and floored the pedal, it did reach 50 but it won't maintain that speed
MAF?

 

[gsxr]

- I did that, I unplugged the pancake socket and floored the pedal, it did reach 50 but it won't maintain that speed
MAF?

I'm not sure. With the MAF disconnected, it should drive normally, i.e. at freeway speeds complete with cruise control. It's possible you have something else wrong too. A digital scanner showing live data is needed to definitely confirm if the MAF is bad. Otherwise you are guessing.

Is your upper engine harness original, or has it been replaced? If original, with insulation crumbling off the wires - you need replace that first, before anything else.

 

[zx10r]

The harness has been changed
I'll bring it to a shop and have it scanned

 

[zx10r]

For today, I cleared out the codes again- The one that comes up is Pin 7 code 6
I disconnected the MAF and confirmed that I can go over 35mph, i went up to 50mph on city streets and I drove the car for 20 minutes
What happened was trying to repeat 50mph was inconsistent. I'd hit 50mph and once I let off the gas pedal, it won't let me get back up to 50 but only to 35mph. Once I'm at a complete stop, I'm able to hit 50 again. This was repeated throughout the 20 minute drive.
I've read Gerry's NSS removal guide and it seems like I may be able to do this for the Pin 7 code 6 problem I keep having
What I'm asking is, what about the MAF now that I disconnected the unit and it does go past 35mph though sporadically?
Is it something I should replace? This is the 2nd unit I got from Ebay and I hear that MAF's doesn't really go bad too often

 

[gsxr]

MAF's are relatively rare failures. But unfortunately you can't confirm if they are good or bad, without live data from a digital scanner (SDS).

That said, MAF will affect fuel mixture only, not throttle control. Limp mode is throttle control only. It sounds like you may have 2 separate issues, but it's hard to tell via keyboard.

Do you definitely have limp mode, with the ASR light on, and the first half of throttle pedal travel doing nothing?

 

[zx10r]

No ASR light comes on, and yes, throttle pedal travel feels like its doing nothing. It feels as though I have to put the pedal to the metal to maintain even 35mph
Check engine light did come on after I turned off the engine and then back on..checked the codes again and 7-6 and 19-10 popped up
But I'm guessing 19-10 was because I disconnected the MAF

 

[gsxr]

Code 10 on pin 19 would be due to a disconnected MAF. Code 6 on pin 7 will likely keep appearing until the NSS is replaced/adjusted.

No ASR light with limp mode is very unusual. Does the ASR lamp turn on when you turn the key on to position 2 (all warning lights on), before starting the engine? And, are all of the lights OFF when driving? If not, which light(s) are on when driving?

 

[zx10r]

ASR lamp and others when turned on to position 2 are lit and all of the lights are off when driving
On another note and or is this a aha moment: The only other thing that I can remember when the car started going bonkers was when I turn on my headlights, the triangle sign appears and that never happened and I can't seem to remove that issue

 

[gsxr]

ASR lamp and others when turned on to position 2 are lit and all of the lights are off when driving
On another note and or is this a aha moment: The only other thing that I can remember when the car started going bonkers was when I turn on my headlights, the triangle sign appears and that never happened and I can't seem to remove that issue

That should NEVER happen. Any chance you have a spare ASR module to swap in for testing? Have you checked all fuses on the BM/GM module?

 

[zx10r]

So I purchased a later model ASR module not knowing until I pulled it out
The part I have is 0265106042
The one I purchased is 0265106078
Will this make a difference?
My triangle light is still on when I turn on the lights after I removed and replaced the module

 

[gsxr]

Those are Bosch numbers... can you post the Mercedes part number for each?

 

[zx10r]

The one in my car
0115454932
The one I bought
0135453932

 

[gsxr]

0135453932 is the correct number for an ASR module, for both .034 and .036 chassis. They are interchangeable with older modules.

 

[zx10r]

Thanks GSXR
I think I’m down to the exhaust for why I’m not going past 35mph
Another hint that might be the culprit is I’m hearing rattling noise coming from the bottom that seems to resonate when I’m at a stop
It does go away when I drive

things I’ve done this week:
I’ve disconnected the MAF one more time to see if I can hit 35mph + and it did go up to 50 but stalled again back to 35
no lights come on

changed the NSS
Cap and rotor
New plugs
Brake light sensor
ASR module

 

[gerryvz]

Are you able to rev the engine up to 5,000 RPM or higher (preferably while moving, not sitting still)? You can test this by keeping the car in a lower gear and accelerating, if you can't go fast on a highway.

 

[gsxr]

Rattling noise under the car COULD be broken catalysts... usually if you smack them with your fist you can tell if the rattle is coming from inside the cats.

 

[zx10r]

Are you able to rev the engine up to 5,000 RPM or higher (preferably while moving, not sitting still)? You can test this by keeping the car in a lower gear and accelerating, if you can't go fast on a highway.

I can rev up to 5000 when I’m parked but not driving

 

[zx10r]

I changed the 2 cats $700 (CA) same result- can't go faster than 35mph- Thank You AAPL for todays price +7
I've owned this car for 10 years and don't mind the investment
But what can it be?
Engine sounds great- no hesitation- no stalling-
Exhaust downward of the cat?
Fuel pump/ Fuel filter?

 

[gsxr]

What codes still appear? Was the rattling noise cured with new catalysts?

If there are zero codes... you could have restricted fuel supply, either from old/failing pumps (possible if they are original), or a clogged tank strainer (unlikely).

 

[Bogeyman]

I've had similar situations twice.
One was related to a turbocharger, so that's out.
The other was restricted exhaust on my '87 TDT.
It caused a severe power restriction and the damndest "coal rolling" ever on an MB.
The pump would pour in fuel according to the accelerator but the engine couldn't burn it all so out the back it came...
I would think that if your exhaust had a similar problem you would notice similar characteristics, although not as black.
So, my guess it is related to fuel delivery and if it starts OK I would tend to blame fuel pump vs restriction.

 

[Jlaa]

@zx10r -- do you still have the triangle sign on the dashboard? I didn't realize that you live so close to me!

 

[zx10r]

@zx10r -- do you still have the triangle sign on the dashboard? I didn't realize that you live so close to me!

Yes..annoying because it only lights up when I turn on the driving lights
I changed out the ASR module but it’s still on

 

[zx10r]

I've had similar situations twice.
One was related to a turbocharger, so that's out.
The other was restricted exhaust on my '87 TDT.
It caused a severe power restriction and the damndest "coal rolling" ever on an MB.
The pump would pour in fuel according to the accelerator but the engine couldn't burn it all so out the back it came...
I would think that if your exhaust had a similar problem you would notice similar characteristics, although not as black.
So, my guess it is related to fuel delivery and if it starts OK I would tend to blame fuel pump vs restriction.

One of the last on the to do list
Fuel filters and pumps

 

[Jlaa]

Yes..annoying because it only lights up when I turn on the driving lights
I changed out the ASR module but it’s still on

Is there some weird ground situation going on? I vaguely remember a thread --- maybe it was from @JC220 or @gsxr wherein they found corrosion in the connector to the CAN box where all the computers are. Even though your cars is mostly in the garage, I do see your car parked outside sometimes so water could possibly have found its way into the connector there?

 

[zx10r]

Is there some weird ground situation going on? I vaguely remember a thread --- maybe it was from @JC220 or @gsxr wherein they found corrosion in the connector to the CAN box where all the computers are. Even though your cars is mostly in the garage, I do see your car parked outside sometimes so water could possibly have found its way into the connector there?

I’ll have to do a double check on the CAN box
Thanks for the suggestion

 

[Provet]

I’ll have to do a double check on the CAN box
Thanks for the suggestion

Do this car have ASR delete mod installed?

 

[zx10r]

Do this car have ASR delete mod installed?

Not that I know of

 

[Etanox]

While you are looking , check if your cable is correct aligned with the transmission.
Could be a lose alignment of the screw making your car limp .
Atleast you can rule that one out already


Regards,

Etanox

 

[jhodg5ck]

Anyone tried an Egas module yet?

 

[Etanox]

Take off the connector behind your dash that is connected to your middle dial where the triangle is . U can see it has a shape that you actually can't possibly plug in wrong .
I tested that theory...
Your switch is plugged in wrong probably. And yes you can plug it in wrong.
Turn 180 degrees and plug it back in .
Problem should be solved.

When u plug it in wrong the cable giving 12 v is switched and it takes the power from your km dash light. Thus when u switch lights on it feeds on wrong pin this causing the triangle to light on .

And 70% sure that this is why you are still limp home mode. The light gives signal to not let you drive /error to your modules somewhat.


I hope that this will help you a bit !!


Greetings

Etanox