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Hello, I have a 2014 E350 that was running perfectly and yesterday the battery died because I left something open and ever since I jump started it this morning it won't shift into anything and says "Do not shift gears visit dealer".
I have a P179A77 code that says "The Redundancy System for DIRECT SELECT Was Activated The Commanded Position Cannot Be Reached." and P179D00 "The Redundancy System for DIRECT SELECT Was Activated".
I would appreciate your guys feedback on this, thanks.
Hello, I have a 2014 E350 that was running perfectly and yesterday the battery died because I left something open and ever since I jump started it this morning it won't shift into anything and says "Do not shift gears visit dealer".
I have a P179A77 code that says "The Redundancy System for DIRECT SELECT Was Activated The Commanded Position Cannot Be Reached." and P179D00 "The Redundancy System for DIRECT SELECT Was Activated".
I would appreciate your guys feedback on this, thanks.
Let's try to save you a big stack $$$$ by not replacing your ISM Module. It has done its job textbook perfect under low voltage.... it is not faulty.
Jumping your flat battery really was the wrong thing to do...
charge MAIN + AUX with a smart charger
then reboot chassis (batt off)
then clear all modules faults
then press brake pedal and shift PRND with ignition-On.
Right now chassis has gone marginal in poor voltage, uncluding AUX has gone low temporarily supplying heavy loads.
> Charge batts and refresh status should resume prior condition. Use a smart charger to protect from stock battery drain.
FYI: flat lead-acid batteries are dead batteries regardless of date code. Replace both when convenient.
Why... the systems in these cars are proven to be sensitive to voltage variations. It best to at least avoid extra straining.
Last edited by CaliBenzDriver; Apr 18, 2025 at 04:11 PM.
Ok thank you, I also have C073200 "No CAN Message Was Received From Control Unit 'Engine'. and C054200 "The CAN Message From Control Unit 'A80(Intelligent Serrvo Module for DIRECT SELECT)' Is Faulty.
Can those steps you just gave still help? Even with these additional codes'
Ok thank you, I also have C073200 "No CAN Message Was Received From Control Unit 'Engine'. and C054200 "The CAN Message From Control Unit 'A80(Intelligent Serrvo Module for DIRECT SELECT)' Is Faulty.
Can those steps you just gave still help? Even with these additional codes'
Thanks
yes, I'd say so.
Feel free to try other ways perhaps more suitable to reach your goals.
All of these faults likely caused by super low voltage near 8 Volts.
Last edited by CaliBenzDriver; Apr 18, 2025 at 08:47 PM.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Fix one thing at a time. This was caused by an electrical issue -- dead battery. When that happens, all sorts of codes would be thrown.
I wouldn't even attempt to charge the battery. Replace it. Then clear all your codes. (What scanner are you using?)
Get a CTEK battery maintainer and put it on the dead battery and see if you can revive it. Then you will have a backup. But dead batteries tend to stay that way.
Last edited by JettaRed; Apr 18, 2025 at 08:46 PM.
Please follow the advice by @CaliBenzDriver and @JettaRed , but most importantly after it is fixed is the summary conclusion: do NOT jump these cars unless you are extremely familiar with their nuisances. It can be a very expensive experience. Always charge the battery with a charger, and the car is NOT a charger.
Fingers crossed it is just the side effect of low voltage.
I tried all the steps, none worked. Under the data stream of the module it says the module isn't personalized or initialized. Does it need to be re-initialized to fix? Or can something else be causing it to say that?
Under the data stream of the module it says the module isn't personalized or initialized. Does it need to be re-initialized to fix? Or can something else be causing it to say that?
If I recall correctly, mine says the same on the E. I would recheck later today
I tried all the steps, none worked. Under the data stream of the module it says the module isn't personalized or initialized. Does it need to be re-initialized to fix? Or can something else be causing it to say that?
The car was was fine before you jumped it... it can't be too far from ok now!!
Can you read scanner data from ISM: PRND Status ?
What are both battery voltage with engine running??
I cannot find the PRND Status on my data stream, but I will go through everything again and double check. However, when the car is running the battery voltage for the MAIN Battery is around 14.8v and the AUX is around 12.8v.
I cannot find the PRND Status on my data stream, but I will go through everything again and double check. However, when the car is running the battery voltage for the MAIN Battery is around 14.8v and the AUX is around 12.8v.
Great!
It looks like your AUX is not powered.
that's what keeps your ISM in limp-mode.
check the AUX nearby charge fuse: red 7.5A.
report your progress towards free repair!
Last edited by CaliBenzDriver; Apr 21, 2025 at 04:03 PM.
The AUX holds at 12.8v whether the engine is off or on, is the AUX battery bad? Also, If you can please elaborate on what "Let's iron out power supply issue by AUX" means please.
I really appreciate it a lot for your help diagnosing this as well. Thanks
Also, I know about the batteries under the hood and in the trunk. However, I'm seeing online something about there being a small one under the steering wheel housing? Can you confirm if that's true?
The AUX holds at 12.8v whether the engine is off or on, is the AUX battery bad? Also, If you can please elaborate on what "Let's iron out power supply issue by AUX" means please.
I really appreciate it a lot for your help diagnosing this as well. Thanks
AUX Batt is supplied through a 7.5Amp fuse that blows under various conditions.
AUX should get chassis voltage with engine running... right now it's only shiwing 12.8... not near 14.88v like main batt.
AUX charge Fuse is the prime suspect.
Check it out !
You can compare yours to mine, and realize the PERMANENT LIMP mode setting is different.
Can you please enter into the TCM module, and check the Driver Authorization entries?
On the AUX battery being at 12.8V, I am only certain mine will go to 14.7/8V for a few seconds after starting up, and winds back to 12.8V. I still have my LIN connected, @CaliBenzDriver that could be the difference. The "smart algo" may switch to 12.8V once the AUX passes the check.
Please check Fuse 88 (15A) in the RearSAM, and Fuse 16 (5A) in the FrontSAM
Also, I know about the batteries under the hood and in the trunk. However, I'm seeing online something about there being a small one under the steering wheel housing? Can you confirm if that's true?
AUX have two distinct incarnation:
tiny alarm size inside dashboard side OR
Motorcycle size in the trunk for ECO feature.
I understand you are dealing with
MAIN in engine bay
AUX in the trunk
There's no 3rd battery...
Last edited by CaliBenzDriver; Apr 21, 2025 at 05:00 PM.
You can compare yours to mine, and realize the PERMANENT LIMP mode setting is different.
Can you please enter into the TCM module, and check the Driver Authorization entries?
On the AUX battery being at 12.8V, I am only certain mine will go to 14.7/8V for a few seconds after starting up, and winds back to 12.8V. I still have my LIN connected, @CaliBenzDriver that could be the difference. The "smart algo" may switch to 12.8V once the AUX passes the check.
Hi JC, yes that makes sense.
It could be that supply side gets disconnected so AUX does not see chassis voltage all day long...
besides AUX monitoring circuit has a displayed fault which we are not seeing here...
Then how to get this good ISM back in gear:
1- clear faults
2- then... what causing ISM "limp mode" activation??
It seems to be responding to its CAN-C very well (not swamped) ✅
Last edited by CaliBenzDriver; Apr 21, 2025 at 05:13 PM.
Hi JC, yes that makes sense.
It could be that supply side gets disconnected so AUX does not see chassis voltage all day long...
besides AUX has a displayed fault which we are not seeing here...
Then how to get this good ISM back in gear:
1- clear faults
2- then... what causing ISM "limp mode" activation??
It seems to be responding to its CAN-C very well (not swamped) ✅
Either a DIRECT SELECT fuse is blown, or the Drive Authorization is failing to complete; therefore, no shifting is allowed. Not certain if his scanner is bi-directional to actuate from the shifter of the TCM module to Neutral.
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