OBD II Fault Code P1791 :

Description of Fault code P1791

VEHICLE SPEED SENSOR (VSS) MALFUNCTION

Possible failuer P1791

• Supply line open
• Signal line open
• Signal line short
• Ground line open
• Sensor failure

Diagnostic Procedure using AutoHex II Scan Tool

• The malfunction is detected when the Engine is started, the voltage from IG1 is more than 10.5V, and the input voltage from VBU to TCM is less than 6V, at least 2 seconds.

Test Conditions using AutoHex tester

• ENGINE SPEED > 400rpm
• Battery Voltage > 10.5V

Clear Fault codes Conditions

• The malfunction is detected when the Engine is started, the voltage from IG1 is more than 10.5V, and the input voltage from VBU to TCM is less than 6V, at least 2 seconds.

MIL Status

• ON

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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