about Autohex II Download forum contact

OBD II Fault Code P1F21 :

Description of Fault code P1F21

Fuel Cell System Battery Voltage Low

Possible failuer P1F21

  • FCVSCM failure
  • Open-circuit of Battery to DC-DC Converter Cable
  • DC-DC Converter failure

Diagnostic Procedure using AutoHex II Scan Tool

  • The rear average wheel speed > 15km/h and vehicle speed on the meter<1km/h
  • If the rear average wheel speed > 15km/h and VSP<1km/h lasts for 0.3 seconds, the malfunction is determined.

Test Conditions using AutoHex tester

  • Vehicle speed / wheel speed is normal
  • Brake is out of action
  • The automatic brake is out of action

Clear Fault codes Conditions

  • The rear average wheel speed > 15km/h and vehicle speed on the meter<1km/h
  • If the rear average wheel speed > 15km/h and VSP<1km/h lasts for 0.3 seconds, the malfunction is determined.

MIL Status

  • Glow ON

GDS KIA Ecu Flashing using AutoHex II


Note:

  • AutoHex II is a professional Auto diagnostic.
  • This fault code is a GERENRIC fault code, some cars may change the meaning of this fault code.
    To get the accurate fault code description you may use AutoHex II

More Fault codes:

OBD II Fault Code P1F22
OBD II Fault Code P1F23
OBD II Fault Code P1F24
OBD II Fault Code P1F25
OBD II Fault Code P1F26
OBD II Fault Code P1F27
OBD II Fault Code P1F28
OBD II Fault Code P1F29
OBD II Fault Code P1F2A
OBD II Fault Code P1F2B
Autohex II Reviews
Autohex II Reviews
Find out Autohex II user's impressions about using this tool for BMW advanced services
AutoHex II
AutoHex II
AutoHex II is your best choice to have full access to dealer functions like coding, adjusting and modules flashing/programming, Contact us for prices
AutoHex Forum
Scan Tool Forum
In AutoHex onboard diagnostic forum you will find discussions how to change the configurations of the car by the professional special functions using AutoHex scan tool
AutoHex II Autohex II For BMW AutoHex II For Kia and Hyundai AutoHex stand alone Mercedes Technical Info