OBD II Fault Code P1786 :

Description of Fault code P1786

FAS SIGNAL FAILURE

Possible failuer P1786

• Signal line open
• Signal line short

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

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

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