OBD fault code library

Look up any P or U code to see what it means, what causes it, the parts involved and how it gets fixed.

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P1721 Gear 1 Incorrect Ratio
Transmission System High severity
P1726 Insufficient Engine Speed Decrease During Self Test
Transmission System High severity
P1728 Transmission Slip Error
Transmission System High severity
P1729 4x4 Low Switch Error
Transmission System High severity
P1730 Gear Control Malfunction 2,3,5
Transmission System High severity
P1731 1-2 Shift Malfunction
Transmission System High severity
P1732 2-3 Shift Malfunction
Transmission System High severity
P1734 Gear Control Malfunction
Transmission System High severity
P1735 First Gear Switch Circuit Malfunction
Transmission System High severity
P1737 Lockup Solenoid System
Transmission System High severity
P1738 Shift Time Error
Transmission System High severity
P1739 Slip Solenoid System
Transmission System High severity
P1741 Torque Converter Clutch Control Error
Transmission System High severity
P1742 Torque Converter Clutch Solenoid Failed On
Transmission System High severity
P1743 Torque Converter Clutch Solenoid Failed On
Transmission System High severity

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