Electrical issues with the 2011 Ford Fiesta

[Alex1978]

Hello everyone,

I just bought a 2011 Fiesta 61. It began to show signs of electrical issues on the inside.
Over the course of a week or two, the infotainment system's primary music unit began to flicker and play only extremely loud FM radio. Eventually, several of the buttons ceased to function altogether. Then, after a week, it would stop working altogether!

The battery earth and all fuses were found to be in good working order. Despite purchasing a replacement battery, the issue persists. No matter what, it had to be replaced.

Here we have yet another issue with the climate control system. The air conditioner reaches maximum heat after three minutes of continuous operation.

So, does anyone have any suggestions as to what could be causing the central infotainment system to not power on and the climate control system to additionally be acting up?

[Alex1978]

https://www.amazon.com/dp/B008FWCLHU?ascsubtag=v1-be0c33-416462-f3d1701e1d-d

[Howard_silver]

If you think it's just a single problem, you can see if the alternator is charging the battery too much by checking the voltage while the engine is running. Different oecus, in my opinion, will withstand an excess of supply, but only up to a certain point.

Beyond that, use Forscan to look for error codes.

[Howard_silver]

OBDLINK EX FORScan OBD Adapter : Amazon.co.uk: Automotive

[Alex1978]

I appreciate your response. 

According to my universal tester, both the alternator and the new battery are in good working order.

The U0164 code is now showing up in Forscan. It could be a fuse, a module, or a connection.

However, how can I tell which of the bigger modules are good and which ones aren't? The fuses appear to be in good condition, but I will double-check them just in case there is a tiny crack that could occur when they start to heat up.

It seems like there might be a connection issue because the air conditioner begins to blow hot air after about three minutes. However, I am not sure which one to use for code U0164, as the problem with the air conditioner could be connected to the reason the radio center unit is not turning on.

The vehicle is a 2011 Ford Fiesta 1.4 Duratec Petrol with the license plate 61.

Kindly share any suggestions based on your expert opinion.

[Alex1978]

https://www.amazon.com/dp/B0DKX5JHDG?ascsubtag=v1-be0c33-416462-b13c6f1d44-d

[Alex1978]

Amazon.co.uk : Ford

[Alex1978]

Amazon.co.uk : Ford Duratec engine parts

[Howard_silver]

The fact that we aren't sure if these are connected problems or if they are merely coincidental makes it all the more difficult. First, you should see if voltage spikes or drops are the culprit. Check the battery voltage as reported by BCM, IPC, FCIM, and APIM (if you have SYNC infotainment) with Forscan PID live date. Assuming the engine is turned on, this should result in a voltage drop of no more than 1 volt relative to the battery reading and definitely more than 12 volts. Not being able to convey any kind of message to them would also be indicative. Stunning, fault codes in every area

To resolve the error code, you can remove it and then check if the problem persists. It might be a leftover from the last time the battery was changed. Forscan has DTCs that you can click on to see when the code was last seen; perhaps it corresponds to the time the battery was disconnected. Another option would be to reset the modules I listed earlier and see if it resolves the issue or clears the error messages.

For the sake of simplicity in diagnosis, let's pretend for the time being that these things are unrelated.

Problem with the air con
So, what's the deal with the air conditioner? Is it that the air conditioner is on the chilly side, and then it's as if you removed it, rendering the "warm" air no different from a cold heater setting in its absence? Alternatively, does it get hot, as if the thermostat were slightly flipped to the hot setting? Is it like the air conditioner actually turns off when you turn the switch off, or does the car act as though it's still on even though it's not?

Given that the radio issue did not exist and that the air conditioner was turned on but failed to cool after a few minutes, it would be more probable that there is an electrical or mechanical problem with the air conditioner circuit. Was the refrigerant pressure checked or topped up recently? After the air conditioner has been running for a while, does the fan turn on? Is the compressor clutch stuck in the "on" position? It might be shutting off the compressor if the pressure was low, the compressor was knackered, or the system couldn't lose the heat buildup.

Entertainment problem
Is there anything visible on the infotainment screen? Is it just that the button that activates the radio and all the other features isn't functioning? If the volume knob were the only component that went wrong and the device stopped turning on, it would appear as though the knob is bust. Have you tried scanning live data for the on/off, vol up/down, and other buttons in forscan? I'm not sure if the data is routed through BCM or not, and I don't have a fiesta anymore, so I can't test. If the forscan doesn't update when you press the knob, it could be a faulty part. However, I'm willing to bet that Ford only sells the entire unit, so you'll have to settle for buying it secondhand.

It would be strange because things didn't go from working to failed; they went from working to not-working-as-well to sort-of-failed. However, you can check the fuses (see owner's manual etc.). There is no "dodgy connection" when using a fuse because fuses are obviously on or off. No middle ground here; fuses are either fine or blown.

[Alex1978]

The aforementioned details are greatly appreciated. I need to get Forscan back on the Fiesta by going through this step by step. Many of the codes probably belong to an earlier era and don't represent the infotainment system.

When turned on, the air conditioner maintains a comfortable temperature of approximately 20 degrees Celsius and continues to run for three to five minutes before suddenly blasting out hot, fully heated air at full speed, completely ignoring the controls. What happens next is that it remains unchanged indefinitely. And I'll have to turn it off afterward. This is a peculiar circumstance. It might have lost pressure, as previously agreed.

[Howard_silver]

Instead of using the dials, I assume you have the digital climate control, is that right? If the air conditioner isn't turned on, what happens? For example, if you turn it to cold, will it go back to full hot after a while?

The car could be fooled into thinking it's colder than it actually is—it could be the stepper motor controlling the valve or the sensors. You are right that we should look into using Forscan, which should display the car's estimated temperature, the user's selected temperature, and the control motor's output (and module voltage). Hopefully, this will help you identify the source of the problem.

[Alex1978]

I appreciate the comments. Valid points to investigate further.

The air conditioning controls are listed below.
The air conditioner turns on and off without a hitch, and I even turned it to the coldest setting; however, after a three to five minute period, it returns to blasting out heat.

[Alex1978]

It has been said that problems with the electrics can arise from a corroded gearbox earth. When this happens, resistance increases and amps decrease, causing various components to either shut off or operate outside of their amperage range. As a result, the ECU will recalibrate them. In any case, I'll have to lift it up so I can check this out.

In addition, I should rerun Forscan and give it another look when I have a chance, maybe over the weekend, when I next deal with this.

[Howard_silver]

By connecting the ohmmeter to the earth connection and the negative terminal of the battery, you can test the main earth. If the earth isn't good, the module or component that earths through that point should experience a voltage drop. You should verify the air conditioner's reported and demanded temperatures by checking the forscan PIDs.

[Alex1978]

I verified the earth connection to the negative terminal of the battery, which is a short, thick black lead barely 8 inches in length. I took off the paint and reattached the body connection under the hood to the painted bodywork connection. There was also no change. I heard that electrical gremlins often originate in the gearbox earth in these fiestas; I should probably find out more about it.
Hopefully, I will verify the PIDs and other values over the weekend.