C0121

C0121 Ford engine fault code diagnosis, code meaning,symptoms and how to fix it.

C0121 Diagnosis

The fuse in the main PDM powering this circuit may be open. The root cause could be excessive loads on an output, or a short to ground in the VBAT2 supply to the CHM.The ICU reads the wiper switch position and sends the status of the switch to the BHM. This fault becomes active when the ICU reads that both LO speed and HI speed are active at the same time.

The BHM measures the current on this circuit when the headlamp output is commanded ON. This fault indicates that the left high beam headlamp circuit is drawing more current than it is designed to supply and possibly there is a wiring fault shorting this circuit to ground.

Ford C0121 Fault Code Meaning :

Ford C0121 Symptoms :

Ford C0121 Reasons :

How To Fix Ford C0121 Trouble Code ?

A code is a fault code and it indicates that something has gone wrong with your car's engine.

It can be caused by many different problems, including a faulty battery, a bad fuel pump, or even a cracked exhaust manifold.

You will need to diagnose the problem before you can fix it. The best way to do this is with an OBD scanner tool.

A scan tool will tell you what needs fixing and how much it will cost in order to fix that particular issue.