Whilst out Cruising today my Z32 tt Auto lost overdrive, the Switch seems ok when turned off o-d off light comes on. Goes through 1st,2nd and 3rd ok.have checked and cleaned plugs in Engine Bay and on trans ECU. Have done trans diagnostics. It has long flash then 10 short blinks then long pause. which I think means line pressure valve. not sure what or where it is. I dont want to start dismantling things if its something simple. can anyone offer ideas?
10 flashes same length means no errors. If the 10th flash was longer than the others, then you have the line pressure valve error.
Check your TPS value (Throttle position), as if it is out by enough the car will not change gear properly. TPS can be measured with a multimeter or using conzult/datascan.
Is your aux engine bay fan kicking in? If so double check your coolant temp sensor and connector. This can play up putting the car into a safety mode as the ecu doesn't know what the coolant temp is so it accomodates for the car being either too cold or too hot by turning on the aux fan and locking out 4th gear.
OD doesn't have as much strain on it as High Gear (3rd) .. I doubt the frictions are gone..but you could have a seal out..the other alternative is the solenoid .. If you don't have a aftermarket trans cooler you might try flushing the complete system , not just dropping the oil pan, but that's just a shot in the dark. A rebuild would most like be in order IF you've never had that done along with a LARGER trans cooler.
I have checked TPS with conzult and thermo switches. the fan is not coming on, However the hydraulic engine fan was stuffed, Has been replaced. Still no Overdrive. When travelling along in third when it boosts under load trans is flairing/slipping. oil levels are correct and trans fluid is near new. Im beginning to think theres a problem inside tranny.
