Workshop test: Test different positions in the gearbox maneuvering. Does the problem persist? If yes, inspect the range manuevering using [Method 1]. If no fault was found, also inspect the inner maneuvering shafts of the gearbox, the forks and the synchronizers. If no, was the error code active multiple times and/or did the driver experience problems? If yes, inspect the range maneuvering using [Method 1] and if necessary the gearbox using [Method 4]. If the driver didn't experience problems, no further action. ----------------------------- Method 1: Inspect air supply and solenoid valve for the relevant maneuvering. Are all the hoses undamaged and is it possible to hear the valve opening/closing when a gear shift is made. Can you hear a leakage when the solenoid valve is not used? Check the cabling and connectors for the relevant position sensor and valve unit for mechanical play, cracked insulation, moisture intrusion in the connector or damaged cabling. Inspect the valve unit internally for moisture intrusion and corrosion on connectors. Inspect that sealings and air pressure cylinder are undamaged and well greased. If applicable, check oil in dampers. Is the oil at correct level? Does the oil have the typical red colour or did water or gearbox oil permeate into the damper oil, causing discolour to the damper oil. Check the rest of the maneuvering unit shafts, levers, springs, dampers etc for damaged articles or distinct scuff marks. Method 4: Inspect the latch for the gear selector shaft in question. Inspect the fastening of levers and fork on the gear selector shaft in question. Check for excessive wear on brass wear pads and on synchronizer parts. Measure the play in the main gearbox. Inspect the support bearings for the retarder are well-assembled, Coupling cone high for form deviations, range fork for form deviations, sun wheel screw is well tightened.

Diagnostic depth