P1764 Nissan -won't change gears.engine light on

Question

Could it be coolant contaminated. .it just happened. What's the best thing to do new transmission or repair? It has 134.000 miles

Answer 1

you will have to drain the transmission fluid to see if there is  coolant contamination inside. if there is it will be a milky red color, instead of redish

have you replaced the transmission fluid? if there is no coolant contamination you can try to replace the fluid and see if it helps, before doing any major repairs.