PISTON 3494367 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
The active codes 585-02 and 673-02 for erratic signals on both transmission output speed sensors usually mean that the ECM sees a large difference between the input speed and the output speed of the transmission. The software expects the output speed to be within a given range for a given gear and a given input speed. In most cases, these error codes are the result of mechanical problems in the transmission and the codes are not the result of a faulty speed sensor or an electrical fault. These active fault codes cannot be erased from the ECM. The fault codes will only be cleared when the ECM detects output speeds within the correct range.Solution
Observe the speed signals with Caterpillar Electronic Technician (ET). Verify that the output speed of the torque converter is accurate by comparing this speed with the engine speed at no load. Observe the stability of the output speed signals during machine movement.If speed sensor signals appear to change with changes in ground speed and the signals are stable, it is unlikely that there is a problem with both sensors. If the machine seems to lack power or if the machine will not move in a given gear, it is likely that there is a mechanical problem inside the transmission. Inspect the screens and filters for debris in order to support this diagnosis. Contact DSN Tier II Support for further consultation before you pull the transmission from the machine.