the acceptable resistance between CN15-147L(blue) and CN15-148G(green) is 1.8 to 2.2k ohms
if pass then check continuity between CN15-147L-CN11-147L-logic card CN1-47L
and
CN15-148G-CN11-148G-logic card CN1-49G
if not pass then replace sensor or repair wiring

if sensor checks good and wiring is good then check logic card, connector and wiring for abnormality
if good replace logics, if not good clean or correct wiring.

you really need to have the tblshooting chart to make sense of this but i'm banking on it being a wiring damage issue, usually around where it connects to the motor from the main harness. Also could be a connector pin backed out of its locked position in one of the connectors too.
seen many a truck where something has got in through the front of the truck and damaged the connector part of the wiring where it connects to the main harness.

as for the H5 code? there is no such code in the manual but the H designates hydraulic circuit and if you have a 5th function installed on the truck then it would be that lever/function that is shorted, like hector says, probably a stuck or misadjusted switch on that section of the valve.

53 Left Vehicle Speed Sensor, Abnormality, Faulty left speed sensor, faulty left speed sensor wiring (wire breakage, shorting), faulty logic card. Check resistance between CN15-147L (blue) and CN15-148G (green) of left speed sensor. Code H5 refers to any attachment lever switch or shorted line lever switch.