Mercedes W213 E-Class Parking Sensor Replacement: Active Parking Assist and Fault Resets

The W213 E-Class is a newer car than most of what comes through with parking sensor faults, and that changes the diagnosis slightly. These cars are far more likely to be specified with Active Parking Assist, and that affects both how many sensors you have and how the system behaves when one fails.

Which cars this covers

• W213 — sedan
• S213 — estate / wagon

Roughly 2017 through 2021 in the US, covering E300, E350, E450, E43 AMG and E53 AMG. The AMG variants share the sensor with the E300 — different bumper, same part.

The earlier W212 E-Class and the W207 / C207 / A207 coupe and cabriolet also use the same sensor family, so if you are on a previous-generation car most of this still applies to you.

The part number

Rear positions and front inner positions take A0009055504. The two front outer corners take A0009055604 — one digit apart, not interchangeable.

Rear bumper only? It is all A0009055504 and the distinction does not affect you.

Why the W213 is different: Active Parking Assist

A W213 with Active Parking Assist runs a more complete sensor array than one with basic Parktronic, and the system is doing more with the data — it is steering the car, not just beeping. Two practical consequences.

First, there are usually more sensors to count, particularly across the front. Do not assume a layout from another E-Class you have owned.

Second, these cars are more likely to hold a stored fault after you have fitted a good sensor. On simpler systems the fault often clears itself after a few ignition cycles. On a W213 with the full assist package, it frequently needs a scanner to clear the code before the system will come back. That is a few minutes at any independent shop, and it catches people out — they fit a correct part, nothing changes, and they assume they were sold a dud.

If you have fitted a new sensor on a W213 and the display is still red, get the code cleared before you conclude anything.

Finding the failed sensor

Ignition on, into reverse to arm the system, then rest a fingertip lightly on each sensor. A working sensor gives a faint rapid tick. A dead one is silent.

A Mercedes-capable scanner will name the position outright — "front inner right" and so on — which on a car with this many sensors is worth the time it saves. A generic OBD-II reader cannot talk to the Parktronic module at all and will return nothing useful.

Why one failure takes the whole system down

The module self-tests every sensor on start-up. If one does not answer, it cannot safely offer partial coverage — it cannot tell you which corner is blind and trust you to compensate — so it shuts the array down and flags a fault.

That is why a single inexpensive part presents like a major electrical problem, and why W213 owners get quoted for module diagnosis when the actual fix is one sensor.

Before you order

Count your sensors. Layout varies with the options package on this car more than most. Walk both bumpers.

Check for bodywork history. Sensors are supplied unpainted and are meant to be colour-matched, but the coat has to stay thin — under about 120 microns of total film. A heavy respray damps the ultrasonic signal until the sensor stops responding. If yours failed shortly after a bumper repair, you have probably found your cause.

Confirm the number, not the model. Build date and options both affect which sensor your car left the factory with. Pull one and read the number moulded into the body, or send a VIN.

Doing the set

The bumper comes off either way, and that is where the labour is. A sensor that has failed at eight years old sits alongside five others of exactly the same age and exposure. Doing the bumper in one go is materially cheaper than doing it twice.

We stock the A0009055504 in singles and in 4, 6 and 12-packs. Free shipping from California, one-year warranty, and we will confirm the part number against your VIN before you buy.

Mercedes Parktronic PDC sensors — singles and multipacks →

Need A0009055604 front outers for a W213? Send us your VIN and we will sort the pair.