GM Service Manual Online
For 1990-2009 cars only

Object Number: 1094691  Size: LF

Circuit Description

The powertrain control module (PCM) calculates gear ratio based on the transaxle input and output speeds. The PCM compares the known transaxle gear ratio to the calculated ratio for the selected gear range. When the PCM detects an unknown transaxle gear ratio DTC P0730 sets.

Conditions for Setting the DTC

DTC P0730 will set if one of the following ratios is detected for 7 seconds

    • Gear Ratio is greater than 3.13:1
    • Gear Ratio is between 2.23:1 and 2.87:1
    • Gear Ratio is between 1.71:1 and 2.02:1
    • Gear Ratio is between 1.07:1 and 1.54:1
    • Gear Ratio is between 0.72:1 and 0.91:1
    • Gear Ratio is less than 0.61:1

when the following conditions have been met:

    • Engine is running.
    • TP angle is greater than 15%.
    • Trans. Fluid Temp. is greater than 20°C (68°F)
    • Vehicle Speed is greater than 8 km/h (5 mph)
    • TFP Range is not Park/Neutral
    • Time since the last gear selector change is greater than 6 seconds
    • No TP Angle DTCs have set
    • DTC P0502, P0503, P0716, P0717, and P1810 have not set

DTC P0730 is a type C DTC.

Diagnostic Aids

    • Check for improper transaxle operation per the chart on facing page.
    • Check for an incorrect calibration.