My car has developed the 5,500RPM limiter scenario. So, can someone be so kind as to tell me where the wheel speed sensor is and how I access it. Secondly, whether I should just disconnect the battery or do the “pump the accelerator x times and then switch on” thing which clears the ECU memory?!
Also, my CAT was refitted a few months back to quieten the car for Bedford, but that was in August and my car has had no problems since, with the CAT remaining in. So I’m guessing although some people say this issue can be CAT related, that my issue is probably a dodgy sensor etc.
Any pearls of wisdom on this subject is most welcome before I get my hands dirty.
take off the offside rear wheel and look for a connector on the leading edge of the lower wishbone. Take apart and look inside. If it looks like its had water ingress clean with a good electrical contact cleaner (cotton buds help) and put back together.
If you follow the cable from the connector to the wheel hub then that’s the actual wheel speed sensor that feeds the ECU.
The sensor (you want) is located on the right hand side rear hub. Pull it apart, give it a clean & spray with WD40.
That may, or may not be the problem though!
In simple terms, if the ECU senses a misfire, it limits the revs to 5500rpm ie limp home mode. It should reset after leaving the ignition switched off for 30 secs.
The difficulty may be in locating the cause of the misfire - it could be the sensor above, dodgy plugs, a damaged vacuum hose, loose fuse/relay (check those in panel behind seats), a different sensor, or a chaffed wire as it passes from the ECU through the bulkhead into the engine bay.
Well, checked the leads, removed the plugs and cleaned them, disconnected the battery to ensure the ECU reset, and then took the car for a spin and the 5,500 problem seems to have gone!
Let’s hope it stays that way!
BTW, the colour of spark points on 1 and 4 seemed more brownish, whereas 2 and 3 were black with powdery look to them. Any insights around this?
My car did the 5,500 thing for the first time the other day… although it was after I’d driven it through a HEAVY rain squall on the way back from my trip down south… I pulled over, turned it off for a few minutes and it’s been fine since… I assumed it was just the sensor had become momentarily fouled by water or something and had triggered the “limp home”