Engine light: ECM-250A / P0172 – fixed, maybe...

[rjenc29]

Hi all

I bought a 2008 V50 2.4i at the start of the OG lockdown to tinker with and for occasional family taxi duties etc.

One recurring problem was that the engine management light would come on after a while; wading through the service history, this seems to have been happening for the last few years, on and off.

The car would start fine, idle smoothly and pull cleanly at all speeds.

It’s been through the hands of three garages (including a main dealer and a Volvo independent specialist) and accrued something like £1,500 of invoices between me and the previous owner for work which didn’t actually fix the problem – albeit this is one of those things that’s not easy to narrow down, and some of the work was probably needed anyway.

Eventually, I came across this post which suggested changing the brake booster vacuum hose (hope it's OK to cross post to another forum):

https://www.swedespeed.com/threads/e...201/?id=401201

I ordered mine from FRF in Swansea, who were extremely helpful and stopped me ordering the wrong part. For righthand drive vehicles, the part number is 30736693 and it cost about £65. It genuinely is a 5-minute procedure to install.

Several journeys and hundreds of miles later, the light has not come back on. Obviously, it will now that I’ve jinxed it, but just thought I’d post here in case it helps anyone else.

For completeness, the things which didn’t actually fix it:
• MAF
• MAP (x2, for reasons)
• Lambda sensors
• Unspecified ‘vacuum hoses’
• Intake manifold gasket (although I’m not sure this was actually done)
• New CEM software, as it apparently has a wider trim limit
• PCV