D 250 Pickup V6-239 3.9L (1989)
Will Not Unlock
1.
Sticking fail-safe valve.
2.
Sticking lock-up valve.
3.
Sticking switch valve.
4.
Valve body malfunction.
5.
Sticking governor valve.
Will Not Unlock
1.
Sticking fail-safe valve.
2.
Sticking lock-up valve.
3.
Sticking switch valve.
4.
Valve body malfunction.
5.
Sticking governor valve.