Fiesta randomly stalling

[Blackbetty]

I have a 2015 fiesta s and I’m having super frustrating issues. The car will randomly will shut off while driving turn on the little wrench light saying it needs to be serviced and shudders and loses power on the way home or to a mechanic. I bring it to a mechanic and the symptoms and light go away on their own, usually before the mechanic can see it. I’ve brought it two different family mechanics and they tell me nothing is wrong with it and then it randomly happens again with no warning weeks later. Has anyone experienced anything like this? I’m at my wits end with this car please help.

 

[LionsTooth]

First place to start is the battery grounds. Clean the cables off at both ends, sand or wire brush the connectors, and the contact points. Intermittent grounds are turmoil for modern cars.

 

[Blackbetty]

First place to start is the battery grounds. Clean the cables off at both ends, sand or wire brush the connectors, and the contact points. Intermittent grounds are turmoil for modern cars.

I actually did that the last time this happened a few weeks ago, the terminals didn't look too crusty but I hit em with sand paper anyway. I'll try doing a more thorough job tonight with a wire brush all over, thanks for the suggestion.

 

[LionsTooth]

Next would be fuel pump ground? The pump is under the back seat. Follow the wires and do the same.

 

[Blackbetty]

Next would be fuel pump ground? The pump is under the back seat. Follow the wires and do the same.

Just so i'm clear, you're saying to clean the contacts for the wires on top of the fuel pump, or somewhere else near the fuel pump? Am I following the wire from the fuel pump or to the fuel pump.

 

[scotman]

A thread started on 13 January of this year titled " Electrical problems" in this section is an excellent visual guide to what Lions tooth is addressing.
Our modern Fiestas are very sensitive to drops in the power supplied to the various electronic devices operating in the car. Those power supply drops or interruptions can be the result of either a weakend battery or, as corrosion that has formed on one or more ground connections.
Any Fiesta that is operated in a consistently damp or salt air environment should have the electrical grounds cleaned and treated with either an protective anti corrosion treatment specific to the purpose or at least a good coating of petroleum jelly on known clean and tight connections by the time their Fiesta is three years old.
Not taking preventative actions is the same thing as inviting ill tempered gremlins to ride along with you in the hope that they won't make trouble. Trouble is what they are all about.
We are slowly creating a fairly comprehensive " Fiesta Electrical grounds maintenance" guide on this forum.
This will become very important to keeping the modern Fiesta running (or, any modern car really) reliably into antiquity. Without maintenance of the electrical grounds and harnesses, all
modern era cars are doomed to electrical system rot.

 

[LionsTooth]

Just so i'm clear, you're saying to clean the contacts for the wires on top of the fuel pump, or somewhere else near the fuel pump? Am I following the wire from the fuel pump or to the fuel pump.

I would identify the ground at the pump and clean its origin at the body.

 

[LionsTooth]

 

[Handy Andy]

A 2015 Fiesta - shuts down and turns on a Orange Wrench light.

Ok, that tells me there is a trouble code getting stored somewhere.

Can you get a code scanner into the OBD-II Connector and just drive until this "quirk" occurs?

Then you may be able to see why that Wrench light comes on.

It could be many things, from a plugged catalytic converter (collapsed innards - broken plugged core) onto an EGR fault - where the piston is stuck open - and the car then hesitates because the piston is a lot like an open vacuum leak - and considerably open - so the engine can't trim mixture right - else it'll throttle at over 3,000 RPM just to run - like it's at open throttle - and exhaust (burned up no fresh oxygen) is the air - not the fresh air it needs to run.

Once the EGR attempts to correctly seat - which will take time. Then the engine can start and run normally - but it has to know how to "reset" - so in a way - once the wrench light turns on - it tries to clear itself thru a series of steps and "positional provisional - aspect" sensing; like Misfires and vacuum - air intake engine temps stuff all gets thrown into a process to tell the PCM "Hmm - hey maybe I goofed - reseat this, reset that - take this and use this value." - until the engine will trim and run well and the O2 sensors, engine misfire and other MAF/MAP stuff says - well I'm fine let's go - condition - and the PCM then takes and reuses the old known values and runs ok until something repeats - WHAM - Wrench light.

Once the piston seats and plugs the vacuum (Read: Very lean) leak from the exhaust, the vacuum for the intake manifold returns and then the engine will run normally. IT can trim the fuel mixture and get fresh air thru the throttle plate. That seems to be the condition that clears itself - but not conditionally - it usually sets a history of this condition and you have to get the vehicle serviced soon enough.

If you ignore this - it can go into "limp in" mode - which is prolly' why your having this performance problem.

​

Another and possibly simpler answer (Occam's Razor applied here) - others are saying it's fuel and rightfully so. Water in the fuel can also cause this condition - and when it gets into the injectors - you lose power - its' abrupt - until the water is pulled out/sucked out and passed into the cylinders thru the injectors - so if you've had a lot of rain as of recently, and refueled after a lot of rain - the last station you visited may be the reason for this problem - water in the fuel and dirt too - if it's that bad.

However - the condition can and seems it does occur again - since it sets a wrench light - it should also do up a trouble code. Knowing the code - That would help isolate this tell-tale condition quicker than guessing by symptoms can.

 

[Blackbetty]

A 2015 Fiesta - shuts down and turns on a Orange Wrench light.

Ok, that tells me there is a trouble code getting stored somewhere.

Can you get a code scanner into the OBD-II Connector and just drive until this "quirk" occurs?

Then you may be able to see why that Wrench light comes on.

It could be many things, from a plugged catalytic converter (collapsed innards - broken plugged core) onto an EGR fault - where the piston is stuck open - and the car then hesitates because the piston is a lot like an open vacuum leak - and considerably open - so the engine can't trim mixture right - else it'll throttle at over 3,000 RPM just to run - like it's at open throttle - and exhaust (burned up no fresh oxygen) is the air - not the fresh air it needs to run.

Once the EGR attempts to correctly seat - which will take time. Then the engine can start and run normally - but it has to know how to "reset" - so in a way - once the wrench light turns on - it tries to clear itself thru a series of steps and "positional provisional - aspect" sensing; like Misfires and vacuum - air intake engine temps stuff all gets thrown into a process to tell the PCM "Hmm - hey maybe I goofed - reseat this, reset that - take this and use this value." - until the engine will trim and run well and the O2 sensors, engine misfire and other MAF/MAP stuff says - well I'm fine let's go - condition - and the PCM then takes and reuses the old known values and runs ok until something repeats - WHAM - Wrench light.

Once the piston seats and plugs the vacuum (Read: Very lean) leak from the exhaust, the vacuum for the intake manifold returns and then the engine will run normally. IT can trim the fuel mixture and get fresh air thru the throttle plate. That seems to be the condition that clears itself - but not conditionally - it usually sets a history of this condition and you have to get the vehicle serviced soon enough.

If you ignore this - it can go into "limp in" mode - which is prolly' why your having this performance problem.

View attachment 4996​

Another and possibly simpler answer (Occam's Razor applied here) - others are saying it's fuel and rightfully so. Water in the fuel can also cause this condition - and when it gets into the injectors - you lose power - its' abrupt - until the water is pulled out/sucked out and passed into the cylinders thru the injectors - so if you've had a lot of rain as of recently, and refueled after a lot of rain - the last station you visited may be the reason for this problem - water in the fuel and dirt too - if it's that bad.

However - the condition can and seems it does occur again - since it sets a wrench light - it should also do up a trouble code. Knowing the code - That would help isolate this tell-tale condition quicker than guessing by symptoms can.

Thank for all the feedback! I just attached an obd II scanner and it gave me a P061B stored code. I know this could mean alot of different things but I figured I'd update.

 

[LionsTooth]

Can you clear the code? If you can, do that to see if that clears the stalling issue or throws the same or a different code

 

[Handy Andy]

Thanks for that...

Here's what Internet has to say...
P061B Internal Control Module Torque Calculation Performance (obd-codes.com)
P061B Internal Control Module Torque Calculation Performance OBD-II Trouble Code Technical Description Article by Stephen Darby ASE Certified Technician

Internal Control Module Torque Calculation Performance What does that mean?

This generic powertrain diagnostic trouble code (DTC) typically applies to many OBD-II vehicles.

That may include but is not limited to vehicles from Mazda, Ford, Mercedes Benz, Chevy, etc.

When a code P061B is stored, it means that the powertrain control module (PCM) has detected an internal performance error in the engine torque monitoring system.

Other controllers may also detect an internal PCM performance error (with the engine torque monitoring system) and contribute to a P061B being stored.

Internal control module monitoring processors are responsible for various controller self-test duties and overall internal control module accountability. Engine torque calculation system input and output signals are subject to self-test and are monitored constantly by the PCM and other related controllers. The transmission control module (TCM), traction control module (TCSM), and other controllers are subject to interaction with the engine torque monitoring system.

Engine torque is monitored (by the PCM and other controllers) using input signals from the mass air flow (MAF) sensor and the accelerator pedal position (APP) sensor (also called the pedal position sensor).

Desired or approximate required engine torque is calculated using the APP sensor and actual engine torque is calculated using data from the MAF sensor. Whenever the ignition is on and the PCM is energized, internal engine torque monitoring self-tests are initiated.

In addition to running internal controller self-tests, the controller area network (CAN) also compares signals from each individual module to ensure that all controllers are functioning properly. These tests are performed simultaneously. If the PCM detects a discrepancy in desired torque and actual torque (more than 50-Newton meters for more than 1-second) with the engine RPM above 5,000 RPM and volumetric efficiency greater than 16-percent, a code P061B will be stored and a malfunction indicator lamp (MIL) may be illuminated.

Multiple failure cycles may be necessary for MIL illumination, depending upon the perceived severity of the malfunction.

Photo of a PCM with the cover removed:
​

What is the severity of this DTC?

Internal control module processor codes should be categorized as severe.

A stored code P061B could result in serious drivability and fuel efficiency issues, suddenly and without warning.

What are some of the symptoms of the code?

Symptoms of a P061B trouble code may include:
Hesitation or stumble upon acceleration
Acceleration becomes unresponsive
Diminished fuel efficiency
MAF or throttle actuator codes are also present

What are some of the common causes of the code?

Causes for this code may include:
Bad throttle valve control servo
Open or shorted circuit in the throttle valve control servo circuit
Clogged air filter element
Debris on the MAF sensor hot wire
Defective APP/MAF sensor
Corroded electrical MAF sensor connector
Defective PCM or PCM programming error
Open or shorted circuit or connectors in the CAN harness
Insufficient control module ground
Open or shorted circuits between the APP/MAF sensor and the PCM

What are some P061B troubleshooting steps?

Even to the most experienced and well-equipped professional technician, diagnosing a code P061B can prove to be quite a challenge. There is also the issue of reprogramming. Without the necessary reprogramming equipment, it will be impossible to replace a defective controller and complete a successful repair.

If there are ECM/PCM power supply codes present, they will obviously need to be rectified before attempting to diagnose a P061B.

Also, if there are MAF/APP sensor or throttle position sensor (TPS) codes present, these must be diagnosed and repaired first. Follow manufacturer's recommendations for testing MAF, APP, and TPS sensors. The oscilloscope can be particularly helpful when testing APP and TPS sensors. Replace failed components as required.

There are several preliminary tests that can be performed prior to declaring an individual controller defective. A diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of reliable vehicle information will be required. An oscilloscope may also prove to be helpful. Connect the scanner to the vehicle diagnostic port and retrieve all stored codes and freeze frame data.

You will want to write this information down, just in case the code proves to be an intermittent one. After recording all pertinent information, clear the codes and test drive the vehicle until the code is reset or the PCM enters readiness mode. If the PCM enters readiness mode, the code is intermittent and will be more difficult to diagnose. The condition, which caused the P061B to be stored, may even need to worsen before a diagnosis can be made. If the code is reset, continue with this short list of preliminary tests. When attempting to diagnose a P061B, information may be your greatest tool. Search you vehicle information source for technical service bulletins (TSB) that parallel the code stored, vehicle (year, make, model, and engine), and symptoms exhibited. If you find the right TSB, it may yield diagnostic information that will aid you in a major way. Use your source of vehicle information to obtain connector face views, connector pin-out charts, component locators, wiring diagrams, and diagnostic flow charts related to the code and vehicle in question.

Use the DVOM to test controller power supply fuses and relays.
Test and replace blown fuses as required.
Fuses should be tested with the circuit loaded. If all fuses and relays appear to be functioning as intended, a visual inspection of controller related wiring and harnesses is in order.

You will also want to check chassis and engine ground junctions. Use your vehicle information source to obtain ground locations for related circuits. Use the DVOM to test ground integrity.
Visually inspect system controllers for signs of water, heat, or collision damage. Any controller that is damaged, especially by water, should be considered defective. If controller power and ground circuits are intact, suspect a defective controller or a controller programming error. Controller replacement will require reprogramming.

In some cases, you may purchase reprogrammed controllers through aftermarket sources. Other vehicles/controllers will require on-board reprogramming that may only be done through a dealership or other qualified source. Unlike most other codes, the P061B is likely caused by a defective controller or a controller programming error Test system ground integrity by connecting the negative test lead of the DVOM to ground and the positive test lead to battery voltage

Read more at: https://www.obd-codes.com/p061b
Copyright OBD-Codes.com

 

[Handy Andy]

What the above means in for you to look into INTERMITTENT electrical and or connector problems.

So since the car is moving, you may have a type of problem that is due to the SHIFTING of torque - or the SHIFTING of a wiring harness - causing an intermittent connection error to occur - hence the "catastrophic failure to Communicate" P061B code to be stored.

It can't isolate the problem, but it does know something is wrong.

When it does that, then that usually tells me it's a failed harness - causing the condition, for if it was a failed part, the part would be noted first and the vehicle will try to clear or test - the condition - the DTC you have is "generic" meaning this was not from a SPECIFIC part failure (range of operation) - it occurred as a condition in the communication of (possible) more than one part - so it's not sure if the parts are at fault or the means(link) to the part is not communicating - the communication link SEEMS to be the condition.