Check the history and pending codes for clues, It could be one of many, from battery voltage to speed sensors to brake light switch..

 

I’ve had a look and there are no codes pending or stored

 

Then its on to monitor live data, see what's amiss

 

It does have to do a self check after every start. If battery cranking volts are getting down then its going to be more frequent

Get a battery load test done and see what the battery is like. Its coming up on 3 years old, and the factory batteries usually start yo fail around that age, about the time the warranty expires.

 

It does have to do a self check after every start. If battery cranking volts are getting down then its going to be more frequent

Get a battery load test done and see what the battery is like. Its coming up on 3 years old, and the factory batteries usually start yo fail around that age, about the time the warranty expires.

Thank you, I’ve been looking for a suitable replacement but am not certain on one that will fit, and my local dealer is not being particularly helpful. Would you be able to recommend a replacement that is suitable for start/stop? Would this fit?

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Have a couple of questions:

What code reader/scanner did you use for diagnosis ?, and
Have you load tested the battery and how ?

 

I wonder if you might be suffering a similar problem to me? My auto stop/start sometimes fails and it does throw up an error P083F. I think this might be a fault with the clutch sensor switch acting intermittently. I have ordered a replacement switch and am just hoping that I'm able to fit it. You can feel the switch or see it but not simultaneously so I'll need to operate my spanner purely by feel in a confined space. Fortunately ebay adverts give me a good view of the switch.

Peter

 

There are in fact two switches. The one shown in the previous post with the black plastic connector is held open when the clutch pedal is not pressed. When this switch is closed by depressing the clutch then the car can be started. A second switch is fitted in the other captive nut and has a white plastic connector. This switch is normally open except when the clutch pedal is pressed. So both switches close when the pedal is pressed. I don't understand why it needs both. I know that when both are pressed simultaneously (i.e. Black open and White closed) it causes a Service Start warning and Auto Engine Stop becomes disabled until Fault Code P083F is cleared.

Peter

 

One is in the starter solenoid circuit so clutch has to be depressed to start (safety feature) the other sends a signal to the bcm/ecm to disable cruise control if the clutch us depressed otherwise its like having your foot on the gas and pressing the clutch. Good test of the rev limiter

 

Thanks GV,
I can understand the need for both functions but I would have thought that both were actually controlled via the ECU. The two switches are simply providing the same information. Is this redundancy for reasons of safety? It seems a bit OTT.

Peter

 

The current required to drive the starter solenoid comes from battery to ign switch thru the clutch switch to the starter in a manual.
Nowhere near the computer systems at all. Old school, reliable and pretty foolproof. Keyless start on the other hand does use the ecm and bcm, but still needs a separate safety switch on the clutch.

The cruise control is actually mostly via the ecm and abs units.

The switches need to be separated as they are totally separate systems.

Wait till you look at the brake switch, thats got 2 sets of contacts, one normally open to run the brake lights and one normally closed that opens when you press the pedal to disable the cruise control. If it doesn't see clutch and brake switches in the correct positions it won't enable cruise set or resume, but will allow the system to turn on.

 

Mine is keyless. If it trusts the switch not to activate the starter solenoid I'd have thought the same switch could be trusted to avoid over revving in cruise. I guess I'm just narked because mine is intermittently causing a Service Start and my attempt to replace one of the switches without major dismantling just resulted in me ripping my hands to bits.

Do you happen to know what a proper dealership would do to replace the switches? The power steering motor is probably the biggest impediment to access.

Peter

 

Have you actually proved its a faulty switch? Or adjustment? Service start system messages can come from many places.

The starter solenoid switch has to be separate from the cruise system,, they are controlled from different units, while you could theoretically use one switch, there will be a very good reason the manufacturer used 2. They cost money.

I've never had to get one out yet so I don't know how the dealer would do it.

 

I haven't proved that I have a faulty switch. The only information I have is P083F error
There doesn't appear to be anything wrong with the operation of the switches and both have the correct rubber pads in good condition. I can't verify that the black switch works but the white one does because pressing that with the clutch pedal up and pressing the start button generates a Service Start error.

Thanks,

Peter

 

You would need a Pro level scanner that is capable of monitoring the individual circuits... Both my Think Tool Pro and X421 MiniPro will monitor these PIDs

 

Do you mean that there is more detail available than P083F?

thanks,

Peter

 

What you have there is a code, not a solution, Just a direction you might follow..

A proper scanner should have the capability of testing and reporting the functions of the buttons and related switches in the circuit..