KZJ78 Overdrive problems

[mzungujerry]

On my 1993 KZJ78 the ATP warning light comes on around 30 seconds after engaging the OD button, at which point the Overdrive ceases to engage. If the OD button is turned off the ATP light goes off. I have checked levels etc - any suggestions?

 

[cicak]

ECU would be my guess.

 

[kbushnz]

solenoid could be sticky or failing and as said ECU..