B1318 – Battery Voltage Low

Meaning:

When the PCM detects that battery voltage has fallen below a predetermined level, the B1318 happens
The B1318 is triggered when the PCM detects that battery voltage has fallen below a predetermined level

This is a Ford and Jaguar code that is set when the PCM detects that battery voltage has fallen below a predetermined level.

Main Symptoms:

Possible Causes:

  • Defective alternator
  • Using an incorrect battery
  • Unmaintained battery
  • High resistance either in alternator-battery circuit, alternator-PCM circuit or both
  • Defective PCM

Diagnostic Steps:

  • Check whether battery voltage is sufficient
  • Ensure battery is properly connected then check alternator belt
  • Using a digital volt ohm meter (DVOM), check whether the charging system is working
  • Reset the code then do a test drive. If the code returns check PCM voltage

Read More: OBD2 Codes List: Meaning, Fixes, and Free Download