P0733

DTC P0733

Steps 1-5:

Step 6:

Steps 7-9:

Circuit Description
The PCM calculates gear ratio based on data from the automatic transmission input shaft speed and vehicle speed sensors. The PCM compares the known transmission gear ratio to a calculated ratio for each commanded gear.
If the PCM detects an incorrect 3rd gear ratio, indicating excessive slip or drag within the transmission, then DTC P0733 sets. DTC P0733 is a type C DTC.

Conditions for Running the DTC
^ No TP DTCs P0121, P0122 or P0123.
^ No VSS DTCs P0502 or P0503.
^ No AT ISS DTCs P0716 or P0717.
^ No IMS DTCs P1820, P1822, P1823, or P1825.
^ The engine run time is greater than 5 seconds.
^ The transmission is not in PARK or NEUTRAL.
^ The time since the gear select lever change is greater than 6 seconds.
^ The transmission fluid temperature is 20 - 133°C (68 - 271°F).
^ The TP angle is 10 percent or greater.
^ The vehicle speed is 5 km/h (3 mph) or greater.
^ The engine torque is 40 - 135 Nm (30 - 100 ft. lbs.).

Conditions for Setting the DTC
The PCM commands 3rd gear and one of the following conditions occurs for 4 seconds:
^ The gear ratio is greater than 3.11:1
^ The gear ratio is 2.23:1 to 2.87:1
^ The gear ratio is 1.71:1 to 2.02:1
^ The gear ratio is 1.05:1 to 1.54:1
^ The gear ratio is 0.71:1 to 0.95:1
^ The gear ratio is less than 0.65:1

Action Taken When the DTC Sets
^ The PCM does not illuminate the malfunction indicator lamp (MIL).
^ The PCM commands maximum line pressure.
^ The PCM freezes transmission adaptive functions.
^ The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records.
^ The PCM stores DTC P0733 in PCM history.

Conditions for Clearing the DTC
^ The PCM commands 3rd gear and detects a correct 3rd gear ratio for 1 second.
^ A scan tool can clear the DTC.
^ The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

Diagnostic Aids
^ Ask the customer about overloading the vehicle, exceeding the trailer-towing limit, or towing in Overdrive.
^ Inspect for intermittent automatic transmission input shaft speed sensor circuit conditions.
^ Inspect for intermittent vehicle speed sensor circuit conditions.
^ Ensure that the current calibration is correct for the final drive ratio.

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 incorrect gear ratio.
4. This step verifies that the correct 3rd gear ratio occurs for commanded 3rd gear.
5. This step tests for low line pressure.