TN75DA CODE 77

   / TN75DA CODE 77 #1  

Ironhorse0484

New member
Joined
Feb 15, 2011
Messages
3
Code: 77 Internal ECM supply voltage (8V) is too high.
Condition: ECM detects that the voltage at ECM connector 2, pin35 is above 8 volts.
Code causes: Faulty ECM. ECM connector 2, pin 35 is/was shorted by an external 12 volt source. Internal circuit short to 12 volts.
NOTE: Connector 2, pin 35 is not used externally as an actual output. There is no wire coming in/out of pin 35. I checked the voltage on the pin. It is at 7.96 volts.
Effects: Transmission is critically disabled. Will not move.
Has anyone seen this problem/code before? Is the controller the only problem or did something else cause the failure? If I install a new controller will the same problem occur and burn up a new controller? Im leaning towards controller because of the code. Other component failures SHOULD throw another code. Any help would be great. Thanks alot.
 
   / TN75DA CODE 77 #2  
There is only one cause for code 77; a faulty ECM. I've changed several ECM's and NEVER had a repeat failure.
 
   / TN75DA CODE 77
  • Thread Starter
#3  
Thanks for the help. I was sure that was it, but another opinion always help.
Sorry on the double post. Just signed up, first time posting, things go that way sometimes.
 
 
Top