The PCM calculates gear ratio based on the transmission input shaft and output shaft speeds. The PCM compares the known transmission gear ratio to the calculated ratio for the selected gear range.
When the PCM detects an unknown transmission gear ratio when 3rd gear is commanded, then DTC P0733 sets. DTC P0733 is a type C DTC.
• | No TP sensor DTCs P0120 or P0220. |
• | No VSS DTCs P0502 or P0503. |
• | No ISS DTCs P0716 or P0717. |
• | No TFP switch DTCs P1810, P1816, or P1818. |
• | The engine is running for 5 seconds or more. |
• | The TFP switch is not indicating PARK or NEUTRAL. |
• | The time since the gear select lever change is greater than 6 seconds. |
• | The transmission fluid temperature is 20-130°C (68-266°F). |
• | The TP is greater than 15 percent. |
• | The vehicle speed is greater than 8 km/h (5 mph). |
The PCM commands 3rd gear and one of the following conditions occurs for 5 seconds:
• | The gear ratio is greater than 3.13:1. |
• | 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 1.07:1 to 1.54:1. |
• | The gear ratio is 0.71:1 to 0.91:1. |
• | The gear ratio is less than 0.61:1. |
• | 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. |
• | 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 ignition switch is OFF long enough in order to power down the PCM. |
• | Inspect for intermittent automatic transmission input shaft speed sensor (ISS) circuit conditions. |
• | Inspect for intermittent automatic transmission output shaft speed sensor (AT OSS) circuit conditions. |
• | Inspect for an incorrect calibration. |
• | Refer to Range Reference . |
• | Ensure the wiring harness is not stretched too tightly or other components are pressing on the connector body. Also, inspect for proper clearance to any other components and wiring. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests for low fluid level, which may cause slipping, and result in an incorrect gear ratio.
This step verifies that the correct gear ratios occur for commanded gears.
This step tests for low line pressure.
Step | Action | Value(s) | Yes | No | ||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||||||||||||||||||
2 |
Refer to Fluid Leak Diagnosis . Did you find and correct a condition? | -- | Go to Step 8 | Go to Step 3 | ||||||||||||||||||||||
Did you perform the Transmission Fluid Checking Procedure? | -- | Go to Step 4 | Go to Transmission Fluid Check | |||||||||||||||||||||||
Important: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the PCM. Did the gear ratio match the specified range? | 3rd: 0.91:1-1.07:1 | Go to Diagnostic Aids | Go to Step 5 | |||||||||||||||||||||||
Did you perform the Line Pressure Check Procedure? | -- | Go to Step 6 | Go to Line Pressure Check | |||||||||||||||||||||||
6 |
Did you complete the repair? | -- | Go to Step 7 | -- | ||||||||||||||||||||||
7 |
Refer to Automatic Transmission Fluid Filter and Seal Replacement . Important: The Clear TAP function will clear all adapt cells. This may affect transmission performance. The PCM will update the adapt cell values as the vehicle is driven. Did you complete the above procedures? | -- | Go to Step 8 | -- | ||||||||||||||||||||||
8 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 9 | Go to Step 2 | ||||||||||||||||||||||
9 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |