Main faults of automatic transmission (Peugeot 406)

Due to the fact that the automatic transmission is a very complex unit, it is necessary to contact a service station to diagnose faults and service the transmission.

Oil leaks

The oil used in the gearbox is usually dark in color. Therefore, do not confuse it with engine oil, which can get onto the gearbox from the engine. To determine oil leaks, clean dirt from the gearbox housing and adjacent areas and conduct a test drive at low speed so that the oil is not carried by the air flow. Place the car on an inspection pit and determine the location of the oil leak. Leaks can occur from three areas: the oil collector, the dipstick tube, and the oil supply area to the heat exchanger.

The gearbox oil is brown in color and has a burnt smell

• low gearbox oil level.

Gear shifting is not clear enough

The gear selector cable is not installed or adjusted correctly. This may cause the following malfunctions:

• the engine can be started in positions other than "P" or "N";
• the indicator shows the selector position not the one that is actually on;
• the car starts moving when the selector lever is set to position "P" or "N";
• fuzzy or erratic gear shifting.

The downshift mode does not work when the gas pedal is pressed all the way down

• low gearbox oil level;
• incorrect adjustment of the gear selector cable.

The engine does not start regardless of the selector lever position or starts in any selector lever position

• the starter lock sensor is incorrectly adjusted;
• incorrect adjustment of the gear selector cable.