2010 Prius won’t start. UO100 code

My father bought a used car once whose previous owner had done that. It became my job to remove the seats and carpet and replace all the melted wiring.

If the specified rating of fuse keeps blowing, that is a sure indication of a problem that needs to be solved before putting another fuse in.

Putting in a higher-rated fuse is simply going to add a bigger problem to the existing problem.

It will be necessary now to find both the original problem that was blowing the 10-amp fuse, and carefully inspect for any further damage done by putting in the 15 amp.

 

How did you get this code and when? Before the experiment with replacing the fuse or after installing 15A instead of 10A?
And yes, the correct code is not UO100 but U0100.

 

P0102
Mass air flow meter voltage less than 0.2 V for 3 seconds

(1 trip detection logic)

• Open or short in mass air flow meter sub-assembly circuit
  
  
• Mass air flow meter sub-assembly
  
  
• ECM
  

• 
  P2237
  Open in the circuit between terminals A1A+ and A1A- of the air fuel ratio sensor while engine is running
  
  (2 trip detection logic)
  
  • Open in air fuel ratio sensor (sensor 1) circuit
    
    
  • Air fuel ratio sensor (sensor 1)
    
    
  • ECM
    

Given the nature of these DTC codes, it can be assumed that you have changed the fuse EFI NO.2.
Therefore, it is important to understand what caused the fuse to burn out, and which consumer.

 

U0100 211 Problem with CAN communication between the ECM and power management control ECU (communication error between ECUs) CAN communication system
U0100 212 Problem with CAN communication between the ECM and power management control ECU (signal transmission error)
U0100 530 Problem with CAN communication between the ECM and power management control ECU (CAN communication system malfunction)

Trouble Area - CAN communication system.

If these errors occur, you must first make sure that there are no other errors, and then check for the presence or absence of error P2532-772.
If DTC P2532-772 is stored, the vehicle will turn off.

 

There is no separate CAN cable, it is an interconnected bus through which data is exchanged between different systems. Trying to rip one pair of wires out of a thick bundle of three dozen wires is pointless.
Error P2532-772 "Ignition Switch Run Position Circuit High" is interesting because power should not be supplied without a command. When power is supplied, this indicates a faulty contact, and what can damage them? A short circuit and an attempt to install a higher fuse rating could fry the contacts and weld them.
You need to find out everything that caused the fuse to burn out and try to eliminate the culprit, a cable, a relay, or some control unit.

 

If the fuse blows, you need to check the circuit from the fuse to those units that receive 12V power through this fuse.

 

double post

 

This is a common job for an auto electrician. Checking the power supply circuits for short circuits.
Mass Air Flow Meter (3), Oxygen Sensor (Bank 1 Sensor 2) (2), Air Fuel Ratio Sensor (Bank 1 Sensor 1) (2), EGR Valve Assembly (2, 5),
Purge VSV (2), Canister Pump Module (5).

This fuse supplies power to several units.
The check procedure is to check for short circuits in the contacts of the units that should be supplied with 12V.
This way you install a probable faulty unit with a short circuit that blows the fuse.
You can disconnect all the connectors of these units, insert a fuse and, connecting the units in series, install the one that causes the problem of a blown fuse when turned on.

 

Those are all the things the EFI2 fuse goes to (EGR, A/F and O2 and MAF) so those codes are probably the result of the fuse blowing.

The more data the better. Does the fuse blow while driving? Does it blow under load or could it happen with the car just sitting there in park? How much drive time and miles are you getting before it blows? Does it seem random? Was anything done to the car recently?

What I would do is get one of those fused wire loops that installs in the fuse slot and allows you to measure current with a current clamp. I would start by getting a reading of that while car is on in park. If it's a high reading I would suspect something is pulling too much current and start unplugging those components. If it's low I would expect more like an intermittent short in which case I'd use a light bulb limiter or circuit breaker to allow me to start wiggling stuff and see if I can recreate it consistently.

It would be difficult to walk you through exactly what to do and possibly dangerous if you don't have a pretty good idea of what you're doing already, so it might be best to take it to someone.

 

Please note that in addition to some unit, there may be a short circuit in the harness wire, which shorts to the body due to poor insulation or rubbing against an element of the body structure. It is better to disconnect all consumers of this line first and check if the wires are shorted to the body, and then connect the units sequentially to find the source of the problem.

You have not five, but six consumers!
Mass Air Flow Meter (3), Oxygen Sensor (Bank 1 Sensor 2) (2), Air Fuel Ratio Sensor (Bank 1 Sensor 1) (2), EGR Valve Assembly (2, 5),
Purge VSV (2), Canister Pump Module (5).