VW Crafter Trans Warning: Oil Cooler Diagnosis Needed

Had the same symptoms on my 2012 VW Transporter 2.0 TDI. The transmission issue turned out to be a failed pressure sensor causing incorrect readings between the oil cooler and transmission control unit. Using professional leak detection equipment, the mechanic found the wiring harness connector to the transmission pressure gauge was corroded and making intermittent contact. This triggered the transmission to enter limp mode as a safety measure. The grinding during shifts happens because the transmission cant properly regulate oil pressure without accurate sensor data. The fix required replacing the pressure sensor assembly and cleaning the connection points. The radiator coolant and transmission fluid were also tested since they share the oil cooler, both were fine in my case. This is a serious issue that needs immediate attention as continued driving can damage the transmission. The failing sensor means the transmission control unit cant properly manage fluid pressures and shift timing. The good news is if caught early, its typically just the sensor/wiring rather than internal transmission damage. Having a proper diagnostic with specialized transmission testing equipment is essential to confirm the exact fault.

Thanks for sharing that, sounds exactly like what happened to my Crafter last winter. The pressure sensor issue caused similar symptoms and the radiator repair was definitely needed too. Did the coolant leak testing reveal any other problems with your system? My mechanic ended up finding a small crack developing near one of the cooling fan mounts. Also wondering roughly what it cost you to get everything fixed? Would help me compare if I got a fair price since these transmission-related repairs can vary quite a bit in cost.

After getting everything checked out by the mechanic, it was definitely just the pressure sensor causing problems with the cooling system, no other leaks or cracks found during testing. The diagnostic equipment confirmed the faulty readings were coming from a damaged wire connection at the pressure gauge assembly. The total repair came to 95€ for fixing the defective cable connection at the pressure sensor. Much cheaper than I initially feared, since transmission repairs can get expensive fast. The cooling system pressure test showed everything else was working normally once the sensor connection was repaired. The car has been running perfectly for several months now with no warning lights or transmission issues. The mechanic mentioned these sensor problems are pretty common on these models, but catching it early before it causes actual transmission damage saved a lot of money. Your cracked cooling fan mount sounds like a separate issue that needed attention. Lucky your mechanic caught that during inspection, problems with radiator coolant circulation can lead to car overheating if left unchecked.

Just wanted to close this thread and share how my repair went. Took it to my regular transmission shop last week. After running their leak detection tests, they confirmed the pressure sensor issue but also found that small crack near the cooling fan mount was starting to affect the coolant flow. Total bill came to 320€, higher than yours since they had to fix both the sensor wiring and reinforce that cracked mounting point on the radiator. Still way better than replacing the whole transmission though. The cooling system is working great now and all warning lights are off. Transmission shifts perfectly again with no grinding. Been driving it for a few days with zero issues. Really glad I got it checked out before any serious damage happened to the gearbox. Thanks again for helping me understand what was going on with this problem. Having your experience to compare against made me more confident when discussing the repairs with my mechanic.