FAULT CODE READING

OBD2 codes.

A code identifies a signal or system that needs to be checked, not a part you should replace.

0 code entries · 1 related fault

P0720

There is no code entry for P0720

13-pin connector leak on the 722.6 gearboxAutomatic gearbox

Engine / equipment: 722.6 five-speed automatic (5G-Tronic), not the 7G-Tronic: C-Class W203, E-Class W210 and W211, CLK, S-Class W220, ML W163, SLK, SL R230, Vito and Sprinter with this gearbox
Period mentioned: 1996–2013
Symptoms: Oil around the electrical connector on the side of the gearbox, harsh shifts or slipping, delayed engagement and limp mode: the car stays in one gear (usually 2nd and reverse after a restart) and the engine light comes on.
Possible cause described: The plastic adapter of the 13-pin connector has O-rings that harden and let oil out. Oil can wick up inside the wiring to the gearbox control unit and damage it. If the problem persists after replacing the connector, there may be oil in the harness, a damaged wire or a conductor plate fault.
Check for the garage: Read the gearbox control unit codes before switching off if possible (a restart can clear them). Look for oil at the connector and, with it unplugged, on its pins and at the control unit plug. According to the service bulletin, the connector should only be removed with gearbox oil below 50 °C to avoid damaging the conductor plate, and the harness must be routed without tension.
Cost cited in the source: Connector adapter: about $15–20 in parts (US prices quoted in the sources), plus the lost fluid; labour extra. If oil has reached the control unit, the repair is bigger.A rough figure from the original database, not an up-to-date quote.