P0730

Description:

Diagnostic Chart:

CIRCUIT DESCRIPTION

The Powertrain Control Module (PCM) calculates the gear ratio based on data from the Automatic Transmission Input Speed Sensor (A/T Input Speed Sensor (ISS)) and the Vehicle Speed Sensor (VSS). The PCM compares the known transmission gear ratio to a calculated ratio for each gear range selected. The Vehicle Speed Sensor (VSS) output is translated to RPM, and may be referred to as Automatic Transmission Output Speed Sensor (A/T OSS).

If the PCM detects an incorrect gear ratio because of excessive slip within the transmission, then DTC P0730 sets. DTC P0730 is a type D DTC.

CONDITIONS FOR SETTING THE DTC

^ No Throttle Position (TP) DTCs P0121, P0122 or P0123 are set.

^ No VSS DTC P0502 or P0503 is set.

^ No A/T ISS DTC P0716 or P0717 is set.

^ No Transaxle Fluid Pressure (TFP) Val. Position Sw. DTC P1810 is set.

^ The engine speed is greater than 500 RPM for 5 seconds, and not in fuel shut off.

^ The vehicle speed is greater than 11 km/h (7 mph).

^ The throttle angle is greater than 14%.

^ The transmission is not in Park or Neutral.

^ The transmission fluid temperature is greater than 20°C (68°F).

^ The engine torque is 70 - 270 Nm (50 - 200 ft. lbs.).

^ 3 seconds have elapsed since last manual range change.

^ All of the above conditions must be true, and one of the following conditions occur for 7 seconds:

- The gear ratio is more than 2.97:1.

- The gear ratio is 2.43:1 to 2.87:1.

- The gear ratio is 1.62:1 to 2.33:1.

- The gear ratio is 1.05:1 to 1.52:1.

- The gear ratio is 0.75:1 to 0.95:1.

ACTION TAKEN WHEN THE DTC SETS

^ The PCM does not illuminate the Malfunction Indicator Lamp (MIL).

^ The PCM commands maximum line pressure.

^ The PCM disables shift adapts.

CONDITIONS FOR CLEARING THE DTC

^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

DIAGNOSTIC AIDS

^ Inspect for intermittent A/T ISS or VSS circuit problems.

^ Ensure that the vehicle's final drive ratio matches PROM calibration. Refer to Range Reference table.

^ Refer to Shift Solenoid Valve State and Gear Ratio table.

TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic table.

3. This step tests for low fluid level, which may cause slipping and result in an undefined gear ratio.

4. This step verifies that the correct gear ratios occur for commanded gears.

5. This step tests for low line pressure.

7. When DTC P0730 sets, the PCM commands maximum line pressure and does not inhibit Torque Converter Clutch (TCC) engagement. This can lead to excessive heat build-up, causing the Torque Converter to 'balloon.' You must replace the Torque Converter.