VW EuroVan Transmission Emulator. Eliminate CEL.

I own a 2003 EuroVan. It’s a great van but it has one major weak point. The 01M or 01P automatic transmission. This transmission is known to fail around 190K miles. Symptoms are hard shifting, a clunk when engaging reverse, not shifting out of 1st gear, sluggish shifting and slipping or not moving at all when hot. It does have a factory oil to water cooler but it’s really inadequate. Adding an auxiliary oil cooler helps but they still eventually fail. A rebuilt unit currently will cost around $6,000 – $7,000 to buy and install.

About 2 years ago, my transmission failed. It went CLUNK and felt like it was in two gears at once with crunchy sounds. Not good. Fortunately it happened at the shop I used to operate so I just parked it. 

An alternative is to install a 02G AFL 5 speed manual transmission. These can be purchased with all the extras you will need from Quality German Auto Parts in Victorville CA. There is currently a waiting list but when they are available they cost about the same as a rebuilt automatic. I bought one  and it came with everything I needed to do the conversion.

There are big advantages to switching to a manual. No more worries about the automatic failing, better fuel mileage and much better performance. Mine van now does 0 – 60 mph in 10 seconds! Not bad for a EuroVan.

There are some issues that come up though. This thread on the Samba forum goes into detail, but suffice to say that the Check Engine Light (CEL) will stay on because the transmission control module (TCM) no longer receives signals from the missing transmission. It will log up to 14 codes for missing signals. If you remove the TCM you will get ABS and stability control warning lights and your ABS will not function. In several states a CEL means you can’t pass yearly inspection and you can’t register the vehicle.


After much research and tinkering I’ve come up with a solution in the form of a hardware hack. First of all, you need to leave the TCM and it’s wire harness that used to connect to the transmission installed in the van. The wire harness is needed to connect to the device I’ve come up with. I call this device the Transmission Emulator. It’s made up of the same solenoids and ribbon cable that is inside the transmission. The external connectors are for the two speed sensors and the valve body harness. There is also a plug that connects to the multi-function switch socket that replaces the switch. The  speed sensor connectors are simply jumper wired. When installed the TCU detects the solenoids, the speed sensors are there and the multi-function switch is in D position. So as far as the TCM is concerned, the vehicle is turned on, not moving and in drive. There is no longer a reason to request a CEL from the engine control module.

Installation is very straight forward. Plug the three connectors into the emulator and install the jumper plug into the multi-function switch. Connect a code scanner, turn on ignition switch, clear all codes and no more check engine light! 

Below are some pictures and wiring diagrams of the emulator. If you are handy with hardware hacking you can build one yourself OR you can send me a donation of $265 shipping included and I’ll send you a unit like the one pictured, complete with instructions,  ready to plug in.


EuroVan multi-function switch pinouts.

Eurovan Multi-function switch internal wiring and pinouts
eurovan transmission solenoid wiring diagram.jpg
Eurovan transmission solenoid wiring diagram.jpg

About Dino

Self taught electronics and hardware hacker.
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