P0730

Diagnostic Chart:

The transaxle control module (TCM) uses the transmission input speed sensor (ISS) and transaxle output speed sensor (OSS) to determine input shaft speed and output shaft speed These sensor readings are used to determine the current gear radio. The TCM uses this information to determine if the commanded gear matches the actual gear. DTC P0730 sets if 1st low gear is commanded and the TCM detects there is no engine braking.

DTC PARAMETERS
DTC P0730 sets if 1st low gear is commanded and the TCM detects an actual gear ratio other than 1st gear when:
^ Ignition voltage is at least 10.5 volts
^ Engine Speed is at least 400 RPM
^ Transaxle has been in a forward gear for at least 8 seconds
^ APP Angle is 0%.
^ Transmission is between 500 RPM and 1260 RPM
^ Trans. Fluid Temp is at least 20°C (68°F)
^ Condition exists for 12 seconds

DTC P0730 diagnostic runs continuously when the above conditions have been met.

The TCM will command Trans Protection mode On if this DTC is active.

DTC P0730 is a type A DTC.

DIAGNOSTIC AIDS

IMPORTANT: If DTC P0717. P0722, P0963. P0973, P0974, P0976, P0977, P0979, P0980, P0982, or P0983 is Set, diagnose that DTC first.

Observe transmission ISS and transmission OSS with a Scan tool. Compare with a known good vehicle to determine if the speed sensors are reading correctly.

Shift solenoids 2 and 4 do not produce any audible click noises when turned on or off. Shift solenoids 2 and 4 can not be tested by listening for audible click noises. Use the symptom chart to determine if shift solenoids 2 or 4 may be stuck open or closed.

Shift solenoid 1 produces an audible click noise when turned ON, but not when turned OFF. Do not replace shift solenoid 1 because it does not click OFF.

Possible causes of incorrect 1st gear ratio:
^ Shift solenoid 1 stuck open
^ Shift solenoid 2 stuck closed
^ Shift solenoid 4 stuck closed
^ Shift solenoid 5 stuck closed
^ Line pressure control solenoid stuck closed
^ TCC lockup pressure control solenoid stuck closed
^ Valvebody
^ Forward Clutch (C1)
^ 1-2, reverse Clutch (B5)
^ Front internal gear sprag
^ Inaccurate speed sensors
^ TCM

1st low gear ratio: 4.602:1 with engine braking