w203 220CDI 722.6 Gear box troubles...

[pnevesfoto]

Hi guys...
long time no hear...
I've been away for quite some time, wich means that I have been out of troubles, but today my Merc laid down some troubles for me to solve...
after a lovely brunch at the seaside, I sat down on my car and turned on the key...
the car started with no fuss but when I placed the lever on D position, I felt a kick from the transmission, and then I realised that something was wrong...

CEL turned on and there was no info on the Gear Lever position on the dashboard...

the car drove initialy with no big changes, but then the lack of changes made the meaning... the gearbox wouldn't change from 1st gear...

after some checking, I realised that the gear lever was stuck on D or N and there was no going back to R or P, unless I turned off the key and then it would change with no problems...

I then read the codes of DTC and it came like this:

• P2135
Powertrain - Throttle/Pedal Position Sensor/Switch "A"/"B" Voltage Correlation

• P2A00
Powertrain - O2 Sensor Circuit Range/Performance Location Bank 1 Sensor 1

• P2553
Powertrain - Throttle/Fuel Inhibit Circuit Range/Performance

• P0705
Powertrain - Transmission Range Sensor "A" Circuit (PRNDL Input)

• P2226
Powertrain - Barometric Pressure Sensor "A" Circuit

I managed to bring my car back home and it is now safely sitting on my garage, waiting for me to see any meaning on this...

I read in some information and other threads in this forum that some people have experienced similar issues with their gear boxes...

Are there any wise words on this malfunction that I should hear?

Can I look for something in specific before jumping into a carshop and pay quite expensive bills that may come around?

I had my trasmission fluid changed 2 year ago (46.000km) and back then I also changed the pilot bushing that was at the time not leaking but menacing to begin to do so...

since then the car drove quite troubleless... until today...

please give me some help around here... I need your expertise and previous experiences...

cheers...

 

[AMGeed]

Have you cleared the codes and tried to drive the car again Paolo?

Your symptoms sound like a faulty gear selector but you obviously need that confirmed.

Hopefully someone with far more knowledge than me can help you.

 

[pnevesfoto]

Have you cleared the codes and tried to drive the car again Paolo?

Your symptoms sound like a faulty gear selector but you obviously need that confirmed.

Hopefully someone with far more knowledge than me can help you.

Hi AMGeed... thanks for your quick answer...

in fact I cleaned up the codes, did a reset to the transmission by pressing the throttle pedal sequence and so on, "et voilà"!... the car was back again, began to drive normaly, but after a few minutes passed, the car went again on the same malfunction... no reverse and no info on the dashboard...

once I was quite near my home, that is why I drove back and parked it...

 

[HB]

Sounds like floor mounted shifter has given up. Same symptoms in my wife's c320 Cdi and £750 later , it was fixed. Arghh!!

 

[pnevesfoto]

I found this on repairpal.com

OBD II P0705
Fault Code Definition

Transmission Range Sensor Circuit Malfuntion (PRNDL input)
Symptom

Check Engine Light will illuminate
Vehicle may not shift properly
Vehicle may not go into gear
Decrease in fuel economy
In unusual cases, there are no adverse conditions noticed by the driver
In some cases, there may be performance problems
Common Problems That Trigger the P0705 Code

Defective Transmission Range Sensor (PRNDL input)
Defective Transmission Range Sensor (PRNDL input) wiring or connector
Defective Valve Body
Defective manual shift valve linkage
Dirty transmission fluid that restricts the hydraulic passages
Common Misdiagnoses

Engine Misfire problem
Internal Transmission problem
Driveline problem
Polluting Gases Expelled

HCs (Hydrocarbons): Unburned droplets of raw fuel that smell, affect breathing, and contribute to smog
CO (Carbon Monoxide): Partially burned fuel that is an odorless and deadly poisonous gas
NOX (Oxides of Nitrogen): One of the two ingredients that, when exposed to sunlight, cause smog
Want to Learn More?

The purpose of the automatic transmission is to match the engine's optimum power and torque characteristics to the driver's desired rate of acceleration and speed by auto-selecting different gear ratios or 'speeds' to power the wheels. The Transmission Range Sensor (also referred to as the PRNDL input and/or neutral safety switch) tells the transmission control module (TCM) and the powertrain control module (PCM) that the transmission is in park, reverse, neutral, drive, low, 2nd, 3rd etc. It is attached directly to the manual valve of transmission, so when the shift lever is moved from park to drive, the Transmission Range Sensor communicates this critical information to the above mentioned vehicle computer systems.

P0705 Diagnostic Theory for Shops and Technicians

When the code P0705 is set in the Powertrain Computer, it means that the Powertrain Computer or PCM is not seeing a clear, rational change in the data and electrical signals sent from the Transmission Range Sensor, especially after the vehicle is in motion. For example, the vehicle is going 25 mph (as reported by the vehicle speed sensor) but the Range Sensor may be reporting that the transmission is still in park. This is an irrational (or impossible) condition. How could the vehicle be going 25 mph and be in park at the same time?

When diagnosing a P0705 code, it is important to record the freeze frame information and then to duplicate the code setting conditions with a test drive at speeds around 15-35 mph. Start out from a dead stop and gently accelerate. Watch the scan data to see if the Range Sensor is reporting accurate information to the TCM and PCM. If the Range Sensor is giving erroneous information or no information to the TCM/PCM, then you may have located a problem that could set the P0705 code. The next step is to start doing pinpoint tests i.e voltage drops and continuity tests of the Transmission Range Sensor. I generally back probe the Range Sensor, so I bypass the wiring harness. This accomplishes 2 things, I'm isolating the sensor from the wring harness and checking the quality of the connector and it's connection. And, ALWAYS check the condition of the fluid. Is it dirty, brown and burnt or is it that clear cranberry color?

I don't know if I can take this as truthful... can anyone advise me on this?

 

[pnevesfoto]

malfunction is gonne... where to???

ok, so I have got some good and some bad news...
let's look at the good news first...
I took a look at the plugs on the TCU/TCM at the feet of the passenger side, and they were bone dry...
did a full reset to the transmission with the throttle pedal again and cleaned up the errors logged in the DTC...
turned on the key, drove for 8 miles on my neighbour area, motorway, empty avenues and small streets... a mixture of driving agressiveness... and to my surprise... everything went on like if yesterdays episode never happened...

wtf???

the bad news:
without the malfunction patent, I cannot diagnose it!!!

what in heaven's name can I do and what the hell was that yesterday in my transmission???

will it be back to haunt me?

what can I expect in the days to come?

please help !!!

thanks...

 

[PobodY]

I'd keep an eye on it, but it maybe just gremlins associated with having been sitting for a while. - You might find it will settle down and behave now.

 

[pnevesfoto]

problem solved...

hello good people...
after a few days the troubles came back for good and I had definatly to make something to sort this out...
I managed to find a PRND selector lever module on a shop that was dismanteling a car just like mine, and changed it.
no more transmission errors or malfunctions...

earlier I got to a point where I needed to have the center console disassembled in order to have the ability to disconect the module plug, on the move, to get control of the transmission...

also while I was with my hands dirty, I changed the throttle pedal that was giving the P2135 errors on DTC... also from the same donor!

now I will send my PRND selector module for repair and keep it tight, hoping never need to use it, but in hand, in case I ever get the same stress again...

 

[Pegasus64]

Where is the prnd sensor located please is that it in the photos you posted many thanks also how can I check colour of transmission fluid please

 

[Pegasus64]

How do you do a transmission reset please

 

[wu56Shoozz]

hello good people...
after a few days the troubles came back for good and I had definatly to make something to sort this out...
I managed to find a PRND selector lever module on a shop that was dismanteling a car just like mine, and changed it.
no more transmission errors or malfunctions...

earlier I got to a point where I needed to have the center console disassembled in order to have the ability to disconect the module plug, on the move, to get control of the transmission...

also while I was with my hands dirty, I changed the throttle pedal that was giving the P2135 errors on DTC... also from the same donor!

now I will send my PRND selector module for repair and keep it tight, hoping never need to use it, but in hand, in case I ever get the same stress again...

Where will you send it for repair?

 

[pnevesfoto]

Where is the prnd sensor located please is that it in the photos you posted many thanks also how can I check colour of transmission fluid please

Inside the PRND lever module, inside your center console, between the two front seats

 

[pnevesfoto]

How do you do a transmission reset please

Seating on drivers seat, insert key, turn to 2nd position, don't start the engine, push throttle pedal to the flor for no less than 15s, turn off the key, leave it there, don't take off the key, now do nothing for 2~3 minutes, absolutly nothing, don't open doors, nothing... Stay put for 2~3 minutes... There you have it... Reset cone!