Hi my first post here. Great diesel forum guys.


I was programing my 2003 LB7 Duramax/Allison with a Hypertech Programer and these codes came up, anything to worry about. Truck is all stock.


Could some one tell me what the error codes U1152, U1026, and C0040 are.


Thanks gpod

DTC C0040 RF Wheel Speed Circuit Malfunction

<?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />DTC U1026 Loss of ATC Class 2 Communication

DTC U1152 Loss of Data HCM

C codes are chassis related, U are network related.