New to VW
Posted: Sat Jul 12, 2025 11:39 am
hey all! writing from the states in NJ. I have come in search of some advice and answers on a friends car I have come upon for some issues it's having, I will do my best to go in order how I've gone upon it so far with its initial problems. I do have a few years experience in the shop's varying from tire shops to emergency vehicle manufacturers maintenance departments which makes me no stranger to diagnosing systems. After my engine rebuild I've taken on side work such as this vehicle and could use some help from your community.
2016 Passat SEL 1.6t vin: 1VWCT7A30GC065538 169,000k
1 owner car since new, paid off, owner is persistent maintenance done as scheduled and in it for the long haul. Vehicle is with me in my driveway which I had towed here to make my life easier. I am currently searching the web and using Chat GTP for most my info which only goes so far without subscriptions I only use once. I did have the owner get OBDEleven Pro package which has unveiled the faults going on. Now onto what's going on.
Transmission: Flares rpm in 1st gear til slips into 2nd, hardly go anywhere. Code's were pointing to sensors,ISS and OSS so I replaced ISS due to OSS being hard wired into the harness. When trans pan was dropped it was pitch black, not burnt smelling or any shavings in the fluid. Tested solenoids on the valve body and were a tad low but threw it back together. Measured fluid in the pan via temp in OBDEleven. Some improvement when shifting but a gear 1 incorrect ratio popped up. Went onto putting a reman valve body in part number matching. Have yet to drive it due to no brakes at the moment which is next issue
I will have live data going to match ISS and OSS when driving next. For the record trans fluid has never been changed which is making me think some internal wear 
Brakes: Pedal has zero power to it but does eventually stop if I don't go over 20mph. checked all calipers,hoses, booster and all checked out. A fault was coming up for the steering wheel angle sensor which I read can have much to do with the brakes in limp mode. tested it and failed miserably. replaced it with a OEM angle sensor from the VW dealer in town and now getting proper voltage but no live reading on OBDEleven just stuck at 0.00 when turning wheel. So started tracing back upstream for the problem.Went onto testing the high and low CAN wire's for voltage at the steering column module connector. Brown ground wire to Orange/green is getting resistance and Brown ground to Orange/brown is 12v. This is to my info the bus lines and their color's. This is where I am not certain on what the pinout and colors are for this vehicle. I have tested every fuse under hood and in vehicle as well for voltage and resistance.
This has been done over some time so bare with me if it's a little all over the place. Basically what I'd like to find is a good wiring diagram for this model, I don't come across much but everything i'm not looking for lol.
2016 Passat SEL 1.6t vin: 1VWCT7A30GC065538 169,000k
1 owner car since new, paid off, owner is persistent maintenance done as scheduled and in it for the long haul. Vehicle is with me in my driveway which I had towed here to make my life easier. I am currently searching the web and using Chat GTP for most my info which only goes so far without subscriptions I only use once. I did have the owner get OBDEleven Pro package which has unveiled the faults going on. Now onto what's going on.
Transmission: Flares rpm in 1st gear til slips into 2nd, hardly go anywhere. Code's were pointing to sensors,ISS and OSS so I replaced ISS due to OSS being hard wired into the harness. When trans pan was dropped it was pitch black, not burnt smelling or any shavings in the fluid. Tested solenoids on the valve body and were a tad low but threw it back together. Measured fluid in the pan via temp in OBDEleven. Some improvement when shifting but a gear 1 incorrect ratio popped up. Went onto putting a reman valve body in part number matching. Have yet to drive it due to no brakes at the moment which is next issue
I will have live data going to match ISS and OSS when driving next. For the record trans fluid has never been changed which is making me think some internal wear Brakes: Pedal has zero power to it but does eventually stop if I don't go over 20mph. checked all calipers,hoses, booster and all checked out. A fault was coming up for the steering wheel angle sensor which I read can have much to do with the brakes in limp mode. tested it and failed miserably. replaced it with a OEM angle sensor from the VW dealer in town and now getting proper voltage but no live reading on OBDEleven just stuck at 0.00 when turning wheel. So started tracing back upstream for the problem.Went onto testing the high and low CAN wire's for voltage at the steering column module connector. Brown ground wire to Orange/green is getting resistance and Brown ground to Orange/brown is 12v. This is to my info the bus lines and their color's. This is where I am not certain on what the pinout and colors are for this vehicle. I have tested every fuse under hood and in vehicle as well for voltage and resistance.
This has been done over some time so bare with me if it's a little all over the place. Basically what I'd like to find is a good wiring diagram for this model, I don't come across much but everything i'm not looking for lol.