2006 - Transmission took a dump

Axiom

Mike from Florida Van Man
So I'm driving my 2006 HC 2500 140" about 5 mins up to the autoparts store. Taking off from a stop light, it shifts into first okay then it tries to shift into second but it gets really sluggish...next thing I know it bangs into gear, lurches me forward a little bit, and I get the dreaded check engine light. Now I'm stuck in first gear and no amount of key resetting is helping me. Can't manually shift either.

I get it home and check the EGS codes on the iCarsoft and it says....

P2203 - Speed sensor 3 is faulty

In CDI, I also had the following codes which I'm sure are unrelated to my problem, yet still triggered:
P2359 - Boost pressure
P2511 - EGR Valve Signal Circuit Shorted to Ground
P2225 - TCM DRC Speed Sensor Voltage Fault Present

About 1000 miles ago, before we started driving this van we dropped the pan, cleaned the valve body and conductor plate, replaced filter, and put in some genuine MB transmission fluid. It also got a brand new plug at the transmission side and the plugs feel dry under the driver's seat going to the TCM.
I have yet to drop the pan yet since I'm a little worried as to what I'll find. But mostly I'm just trying to figure out if speed sensor 3 is part of the wheels or on the conductor plate?

Cheers!
 

Midwestdrifter

Engineer In Residence
P2203 Speed sensor 3 (X106b5) is faulty
a. Cable A4.2135 to X106x1/1 has a short circuit to ground(-) or open circuit. or short circuit to voltage {+).
b. Cable A4.2113 to X106x1n has an open circuit.
c. Cable A4.2/33 to X106x1/12 has an open circuit.
d. Speed sensor (X106b5) is faulty.
e. Valve body (X106) is defective.

The N3 sensor is located on the conductor plate. This code indicates a wiring or conductor plate fault. Double check your harness connections. If they are good, unplug the TCM, and ohm out the wires going to the N3 sensor. The attached manual has a resistance spec for it somewhere.
 

Attachments

Patrick of M

2005 T1N 2500 (NA spec)
I have had a speed sensor failure in the transmission that was intermittent (it went into LHM very inconveniently but once cleared didn’t reoccur for 4 months). Then it got got worse. I ended up changing the contact plate (as well as the connector etc). THE 2nd gear and 3rd gear speed sensors are known to fail. That being said can your scanner clear the LHM? If so you can take a drive and monitor live data to see what is going on before going into a lot of trouble shooting/diagnosis. My scanner can observe VSS for 2nd and 3rd as well as a number of other parameters, it should be possible to narrow your focus if the vehicle will test drive. If it goes right back to LHM after properly clearing the LHM, without even driving the vehicle, I would suspect wiring more than VSS although a thoroughly blown VSS would also be able to trip LHM without moving the vehicle.
 
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220629

Well-known member
The multitude of other DTC's would have me hoping for a wiring/harness issue of some sort. Rather than dropping the tranny pan, the first thing that I'd do would be to check at the TCM under the driver seat for fluid contamination.

:cheers: vic
 

Midwestdrifter

Engineer In Residence
Also
P2225

This indicates a wiring issue to the speed sensors. They have a common votlage supply (they are hall sensors) So I would check the ground and common supply wire. You should also verify there is good 12v power supply to the TCM.
 

Axiom

Mike from Florida Van Man
I have had a speed sensor failure in the transmission that was intermittent (it went into LHM very inconveniently but once cleared didn’t reoccur for 4 months). Then it got got worse. I ended up changing the contact plate (as well as the connector etc). THE 2nd gear and 3rd gear speed sensors are known to fail. That being said can your scanner clear the LHM? If so you can take a drive and monitor live data to see what is going on before going into a lot of trouble shooting/diagnosis. My scanner can observe VSS for 2nd and 3rd as well as a number of other parameters, it should be possible to narrow your focus if the vehicle will test drive. If it goes right back to LHM after properly clearing the LHM, without even driving the vehicle, I would suspect wiring more than VSS although a thoroughly blown VSS would also be able to trip LHM without moving the vehicle.
I can clear the LHM and probably drive for about another 10 minutes until it warms up and it happens again. I'll try and monitor transmission parameters when I take it for another test drive.
 

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