got2bharmony

Thanks for your reply. It was originally showing multifunction switch problem but now showing other errors and on dash frequently says no gear selected. I've started to look at the mutlifunction switch on side of transmission. Can't see any obvious damage but haven't yet tested pins whilst selecting gears. Do you know if the switch can be removed without removing trans left side support? Do you know if multifunction switch can be opened and any possibility of cleaning it etc? They are 250 UK pounds to buy, so don't want to buy one and then find it is problem in the tip control unit. Any advice/help gratefully received. This is going to consume many hours if I have to check everything a step at a time. Alan

I've had a problem developing over the past few months with various errors registering with the Tip. First I got the flashing 4/M red LEDs and limp mode. Codes read with PST2 indicated multi-function switch problem. Error could be cleared. Sometimes the error code would differ, but would always reset. Time between errors varied but became more frequent. I researched possible causes and I was directed to one of three things: Faulty multifunction switch on left hand side of transmission. Faulty selector switch Cable between the two switches. I could see no problem with the cable, so decoded to focus on selector level. The PST2 diagnostics has limited real time data sampling but it failed to report valid values with D or M selected, only P and R were indicated correctly on both switches. I have removed the selector and checked the 6 wires with a test meter. The manual switch (brown and blue wires) is clearly fine as confirmed by the PST2 data sampling. In terms of the other 4 wires, irrespective of the selector level position only the yellow and black wires are closed circuit. This surely confirms a switch problem assuming all pairs are normally open switches and not more complex signal modulation. I've ordered a replacement used JOPP 987.426.011.01 AS02 on eBay and hope it will be the solution. Does anyone know the pin outs for the yellow, black, green, brown (not manual switch pair) are, ie what lever positions correspond with wire contacts. I suspect the black is a common ground, but I could be wrong. Has anyone managed to disassemble the JOPP switch and fix contact problems? I haven't yet proven there isn't a problem with the multifunction switch on the transmission, but it's a significant job to remove, so I'll hope the selector turns out to be the only issue.