Restricted Performance Mode ...on Left Turns?

[Wayze]

Hey guys, I've been dealing with this headache for 10 months now... My 2016 F-Type R (U.S. Version) keeps going into "Restricted Performance" mode, and is most easily repeatable by accelerating and turning left...

Multiple mechanics have believed they've fixed it, only for it to work for 3-4 days and then it returns to this behavior. Each time when the issue re-emerged, the Restricted Performance mode only limited the car to 40mph with no other effects. Over time, the speed gets more and more restricted until it's around 3mph and the idle becomes very rough. I cannot for the life of me figure out why this mode would be repeatable by turning left and somehow also related to the rough idle..

So far we've replaced:

• Throttle Body
• Accelerator Pedal
• ECU (twice)
• BCM
• Battery
• Boost Sensor
• Low Fuel Sensor
• Engine Wiring Harness

The codes it was initially throwing were:

• P06A7: Engine Management System Performance.
• P2127: Throttle/Pedal Position Sensor/Switch 'E' Circuit Low Input.
• P0122: Throttle/Pedal Position Sensor/Switch 'A' Circuit Low Input.
• P0221: Throttle/Pedal Position Sensor/Switch 'B' Circuit Range/Performance.
• P2135: Throttle/Pedal Position Sensor/Switch 'A' / 'B' Voltage Correlation.
• P0237: Turbocharger/Supercharger Boost Sensor 'A' Circuit Low.

It's at it's fourth mechanic now and he is going to see if these codes have changed.

Does anyone have any ideas on what could be causing this? Any information or leads would be very much appreciated as I'm losing my mind ha. Thanks in advance!

[simpleR]

P06A7 is the PCM (Powertrain Control Module) confirming it has received a bad signal.

The multiple throttle error codes are all generic suggesting that the power requested by the throttle position were not obtained.

P0237 is also generic.

I see you have posted on multiple other forums over the past year but with some different info. Happens when it's hot, or over bumps, head light flickering etc. Quite a few various symptoms and issues.

So. Based on everything seen on this forum.
Number 1 battery.
Number 2 main earth strap is corroded or loose. See viewtopic.php?t=4482 (remember some notes and terminology will be for UK with steering wheel on the opposite side!).

And Hi and Welcome. Pictures are required over here. Let us know how things progress. Forums tend to bring people to join as they have issues but hope we can help.

[paddy1000111]

From your description and the fact it's left hand turns it sounds to me like a loose plug or a harness thats rubbed through and the acceleration/left turn combo is causing it to short. I'd suggest getting all the engine covers and plastic off and with the engine running give all the cables a wiggle maybe with a little tug/pressure to the right side of the vehicle. Do the same under the dashboard in the footwell on both sides.

[Kev]

I concur with the above given it only happens on left hand turns, it’s pointing to a loose connection or a wire that’s been stretched with the conductor within causing a high resistance, or somethings rubbed through and shorting. It’s back to basics and the wiggle test

[cj10jeeper]

Agreed - this needs a systematic following of all the main looms and connectors end to end where visible. It's going to be a painful elimination process of pull, push, wriggle, flex, with no guaranteed quick results. I'd start around the engine area first, then the battery area, earths then start on the end to end stuff. Could also try loading the system with lights, fan heater, seats heaters, etc. to see if anything induces an issue

I do empathise with you . A good few years ago my wife had a Peugeot, brand new that every few days simply stopped, always from quick acceleration from lights, junction, etc. Super embarrassing given where it stalled out. Impossible to replicate at the dealers. Eventually tracked to a main loom connector in the footwell, not locked in from factory build. Jolt of acceleration stressed it enough to cause a stall.