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CarDoc, Auto Mechanic
Category: Car
Satisfied Customers: 508
Experience:  IMI L3 Motor Vehicle Mechanic
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I have a fault with my fiat 500, replaced the map sensor but

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Hi I have a fault with my fiat 500, replaced the map sensor but car still has fault. When car is idle it goes into limp mode.
Assistant: Which particular sensor are you asking about? And have any trouble codes been triggered?
Customer: Yes code P0101
Assistant: What year is your 500e?
Customer: 2015
Assistant: Are you fixing your 500e yourself? What have you tried so far?
Customer: Replaced the map sensor & it’s been in the garage today but they can’t find the fault
Assistant: Anything else you want the Mechanic to know before I connect you?
Customer: Garage said it is an electrical fault just want to know if mechanic has any idea what it can be

Thank you for using JA. I'm Baz, one of the automotive experts, I try to be available in the afternoon on weekdays and in the evenings on the weekend. I apologise if I do not respond to your question promptly, I can assure you that I will respond as soon as I can. Thank you

P0101 relates to the MAF sensor not MAP sensor. The MAF is found on the intake pipe, just after the air fliter box.

When was the air filter replaced?

Customer: replied 6 months ago.
Air filter was replaced in April when it was serviced it does not have a MAF Sensor

You need to check the wiring to the MAP sensor. Are you 100% sure there is no MAF sensor because that fault code is specifically for the MAF sensor, strange.

Customer: replied 6 months ago.
100 % sure there is no MAF sensor it has been checked by AA & Garage.
Customer: replied 6 months ago.
MAP sensor has been replaced but still has fault

Check for power, ground and signal from the MAP sensor wiring and also check live data feedback from the sensor with a diagnostic tool. You have replaced the sensor but if there is a problem with the wiring then a new sensor will not change anything.

If you're doing the work yourself, then I can guide you on how to check the wiring.

Hope this helps.

Customer: replied 6 months ago.
Please can you guide me on how to check the wiring

Put the ignition in the ON position. Get a paperclip and backprobe each wire (1-by-1) and use a multimeter to find the power wire and then ground. Connect the black lead to battery negative and use the red lead to find the power and ground, you should get 5v on the power wire and 0v on ground then the 3rd will be the signal wire.

Once you know which is the signal and ground, backprobe the ground and signal, then connect the black lead to the ground and red to the signal and start the engine. You should be at around 1v and as you accelerate, the voltage should increase to around 5v. The voltage numbers aren't important, what's important is that the voltage increases as you increase the revs.

Please let me know the what you come up with. Thank you

Customer: replied 6 months ago.
Ok thanks will give that a try

Welcome, if you have any problems, let me know on here.

Thank you for using JA!

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