Codes 84 and 99

[Jon E]

I need some help. I have a 1994 6.5 TD, rebuilt recently with new injection pump, new injectors, new glow plugs, new glow plug controller, and a new EGR solenoid. Before the rebuild it would blow lots of white smoke at startup and the SES light would come on when I was idling at a light, but go off when I accelerated, it would puff white smoke then too. After the rebuild the problem is still here, the mechanics keep fixing more things they say are a problem but it keeps occurring. I just did the self-test for the trouble codes and I have a 33, 84, and 99. I think I know what the 33 is from, but the 84 and 99 stump me. I don't know that much about the engine. Could someone please let me know what the 84 and 99 codes mean.

[charliepeterson]

Could someone please let me know what the 84 and 99 codes mean.


These are both Accelerator Pedal Position (APP) codes. Look carefully at the wire harness for any nicks or bad connections.

Did you notice a "Service Throttle Soon" light?

You most likely lost the pedal assembly.

With key on engine off pull the harness off the assembly and probe pin #D for 4.5-5 volts. If yes then you lost the module.
Most likely the new module will come as an entire assembly so don't try too hard to get the module off the accelerator.

[Jon E]

There was no "Service throttle soon" light on, just my SES light intermittently.