about Autohex II Download forum contact

OBD II Fault Code P1656 :

Description of Fault code P1656

OTHER UNIT SIGNAL FAILURE

Possible failuer P1656

  • Signal line open
  • Signal line short
  • VSA control unit failure

Diagnostic Procedure using AutoHex II Scan Tool

  • The PCM/ TCM monitors the actual mainshaft speed (rpm) and countershaft speed (rpm) ratios and the commanded ratio. The PCM/TCM computes these ratio continuously.
  • A malfunction is detected when a difference between the actual ratio and the commanded ratio occurs, and it is over the specific ratio.
  • When the 3rd -> 4th upshift has been made then the PCM/TCM detects neutral position while driving in 5th gear a malfunction is detected.

Test Conditions using AutoHex tester

  • D or D3 shift position
  • Battery Voltage > 11V
  • Upshifting 1st through 5th

Clear Fault codes Conditions

  • The PCM/ TCM monitors the actual mainshaft speed (rpm) and countershaft speed (rpm) ratios and the commanded ratio. The PCM/TCM computes these ratio continuously.
  • A malfunction is detected when a difference between the actual ratio and the commanded ratio occurs, and it is over the specific ratio.
  • When the 3rd -> 4th upshift has been made then the PCM/TCM detects neutral position while driving in 5th gear a malfunction is detected.

MIL Status

  • OFF

Changing Dmaged DME in F Series


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 P1657
OBD II Fault Code P1658
OBD II Fault Code P1659
OBD II Fault Code P165A
OBD II Fault Code P165B
OBD II Fault Code P165C
OBD II Fault Code P165D
OBD II Fault Code P165E
OBD II Fault Code P165F
OBD II Fault Code P1660
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