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I had the following errors pop up, initially one P2442, cleared DTC, then a few days later both P2442 and P2440.
P2440 – Secondary Air Injection System Switching Valve Bank 1: Stuck Open
P2442 – Secondary Air Injection System Switching Valve Bank 2: Stuck Open
I did a quick search of the C63 forum and didn't find any posts on this issue. There is one post on the CLK forum (https://mbworld.org/forums/clk-class...ode-p2442.html) but as our M156 engine is different, for completeness, am posting info here.
P2442/0 errors could be either the left / right valves, or the air pump ... but on inspection I noticed a vacuum line had perished / deteriorated quite badly (see photo for location; new hose installed).
Swapped in some new hose (re-used the blue one-way check valve) and the DTCs have not returned after a week of driving.
Valves and / or pumps can fail, but sometimes it's a cheap fix like a vacuum line or electrical connection.
04-23-2019, 03:31 AM
