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Topic: Allison fault code and intermittant retarder (Read 849 times) previous topic - next topic

Allison fault code and intermittant retarder

Just an update to my code (D1-4523) showing H solenoid open which results in inhibiting retarder operation. Found a very dirty two pin connector that goes into the area of the H solenoid on the rear of the transmission just next to the dip-stick & oil fill tube area.
 
Sprayed that nasty dirty connector very liberally with Deoxit and used an air nozzle from my portable compressor to blow air across the connector to create a venturi effect to suck out the dirt and deoxit liquid. I did this twice and the connector is clean and shiny.

cleared the codes and off over the mountains (twice) at White pass near Mt. Rainier. So there was a lot of retarder use. And I'm happy to report that the retarder worked like a champ with zero issues.