Serena Brake Booster Pressure Sensor

Whoa, sounds familiar! I had a similar nightmare with my old BMW 3 series – completely different car, I know, but the brake system gremlins were almost identical. ABS light flashing, spongy pedal, the whole shebang. Did you check the sensor readings with a decent diagnostic tool? If the pressure readings are all over the place, it could definitely point to a faulty sensor or air trapped somewhere in the lines. Bled incorrectly? That’s a classic way to introduce air into the system. You getting any weird noises from the ABS pump?

When you had this with your BMW, did the diagnostic tool specifically identify the brake booster pressure sensor, or was it a general ABS error? Also, is there a bleeding sequence that's more prone to introducing air on these vehicles?

The diagnostic tool on my Beemer threw a code directly related to the pressure sensor, thankfully. Saved me hours. As for bleeding, some systems are super sensitive to the order. I vaguely remember reading that Nissans can be a pain. Honestly, unless you're really confident with brake systems, I’d suggest taking it to a workshop. Brakes are NOT something to mess with if you're not 100% sure what you're doing. Could be a cheap sensor fix, or it could turn into a bigger problem if you screw something up.

I brought the Serena to a trusted workshop. It turned out that the brake booster pressure sensor was faulty, likely from a previous improper brake bleeding, just as you suspected. The total repair cost was about 90€, which I consider reasonable for restoring proper brake performance. Thanks again for sharing your experience; it helped me steer the diagnosis in the right direction.