Had my 2005 1.8 S40 for two years now, when I got it had some electrical gremlins CEM clean sorted those been good as gold since, at the moment I'm having what I think is also an electronic issue when driving all the dash lights illuminate and throttle response/acceleration becomes non responsive and the speedo drops, it only lasts less than a second or two and normally a gear change fixes the issue, no codes and there is not pattern as to when it happens.

Had a new battery and alternator in the last 12 months, probably going to pop out the CEM for another clean and check other electrical connections, any other suggestions for things to look out for?

 

the speedometer is driven by a speed sensor that feeds into the ABS computer and TCU then up to the ECU. I'd suspect that you may have an issues with the ABS computer or TCU. Check out Midwest ABS or XeModex's web pages for any guidance on symptoms / diagnostics for the ABS board. You can also try cleaning the contacts and reinstalling both to see if that helps. You can also research on which sensor(s) are in play for the speedo for your year/transmission.

 

Many thanks for the advise.

I'll have a look and see whats what.

I was under the car this weekend and went through fuses and CEM, a lot of them looked a little corroded so tidied them up and replaced a couple, turned her over and so far so good

 

Great with these older cars electrics play havoc as things corrode , we are quite lucky in JHB RSA as its quite dry here so things do not corrode so much

 

So there was a development after having the issue for a a while the car threw out a P0320 DTC, pointed to a speed sensor issue, changed out the camshaft and crankshaft position sensor and the issue seems to have been resolved, the old one was caked in oil, so folks use a funnel when topping up

The camshaft sensor was a piece of ****, the crankshaft sensor was trickier but doable without getting the car in the end