This has been getting worse recently. I didn’t have any problems for months, then recently I’ve been experiencing very brief periods (one or two seconds) of the Home Safe Mode where the car will slow to 30mph / 2,000 revs, this appears to happen at any time, any weather, any speed, which could be quite dangerous especially at high speed, in slippery conditions, or critical moments in heavy traffic.
I have been intending to check the repair job that the garage did on the crank shaft sensor (I think this is also known as the TDC – Top Dead Centre – sensor, generally described as the main cause of starting problems); yesterday the car performed horribly! It would keep going in and out of Home Safe Mode, and at one point eventually just stopped, gave me no power at all as it just died on a hill, then wouldn’t start. A wiggle of the TDC wiring and it worked fine all the way home.
Today I took the insulating tape off the wiring join that the garage had done to connect the new connector (for the TDC sensor) to the wiring loom, upon removing the tape one of the wire joins just fell apart, the other came apart with a gentle tug. Absolutely pathetic! Not only the poor job done by the mechanic, but also the cheap join hardware provided with the sensor which was little more than a metal ring covered in cheap clear heat shrink.
I removed the offending heat shrink and metal ring, cut back the wire to get a fresh bit to join, then soldered the wires together and covered in proper electrical heat shrink. Car started straight away, revved up nicely, remained running on tick-over for several minutes, and restarted fine several times after that.
We will see how it runs now. I suspect that the Lambda sensor still needs looking at so I will take the car to a garage as soon as possible (there is a local Wilco Motosave, they were very good when they replaced the battery and front coil springs).