DTC P0731 Non-European Emissions
Circuit Description
The transmission control module (TCM) uses transaxle input speed information and output speed sensor to control line pressure, torque converter clutch (TCC) apply and release and transaxle shift patterns. This information is also used to calculate the appropriate operating gear ratios and TCC slippage.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0731 Incorrect 1st Gear Ratio
Conditions for Setting the DTC
| • | Time since TCM reset is greater than 500 ms. |
| • | Time since shift end is greater than 500 ms. |
| • | Transmission oil temperature is greater than -10°C (14°F) |
| • | System voltage is greater than 9 volts |
| • | No input speed error DTCs P0715, P0716, and P0717 |
| • | Output speed is greater than 256 RPM. |
| • | Input speed is greater than 400 RPM. |
| • | No gear shift active |
Action Taken When the DTC Sets
| • | The hold lamp will blink. |
| • | The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer. |
| • | Adopt Emergency/Substitute mode and constant 4th gear. |
| • | High line pressure |
Conditions for Clearing the Hold Lamp/DTC
| • | The hold lamp will turn OFF when the malfunction has not occurred after 3 ignition cycles. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | Using a scan tool can clear history DTCs. |
Diagnostic Aids
| • | Inspect for intermittent input speed sensor or output speed sensor circuit problems. |
| • | Inspect for possible incorrect calibration. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 | Visually inspect the transaxle cooling system for fluid leaks. Was the condition found and corrected? | -- | Go to Step 7 | Go to Step 3 |
3 | Has the transaxle fluid checking procedure been performed? | -- | Go to Step 4 | |
4 |
Does commanded gear ratio match ranges as shown? | 1st = 2.719 2nd = 1.487 3rd = 1.000 4th = 0.717 | Go to Diagnostic Aids | Go to Step 5 |
5 | Perform a line pressure inspection. Was the condition found and corrected? | -- | Go to Step 7 | Go to Step 6 |
6 | Inspect for possible clutch slippage. Was the condition found and corrected? | -- | Go to Step 7 | -- |
7 |
Has the last test failed or is the current DTC displayed? | -- | Go to Step 8 | System OK |
8 | Replace the transaxle assembly. Refer to Transmission Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Has the last test failed or is the current DTC displayed? | -- | Go to Step 2 | System OK |
DTC P0731 European Emissions
Circuit Description
The transmission control module (TCM) uses transaxle input speed information and output speed sensor to control line pressure, torque converter clutch (TCC) apply and release and transaxle shift patterns. This information is also used to calculate the appropriate operating gear ratios and TCC slippage.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0731 Incorrect 1st Gear Ratio
Conditions for Setting the DTC
| • | Time since TCM reset is greater than 500 ms. |
| • | Time since shift end is greater than 500 ms. |
| • | Transmission oil temperature is greater than -10°C (14°F). |
| • | System voltage is greater than 9 volts. |
| • | No input speed error DTCs P0715, P0716, and P0717 |
| • | Output speed is greater than 256 RPM. |
| • | Input speed is greater than 400 RPM. |
| • | No gear shift active |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer. |
| • | Adopt Emergency/Substitute mode and constant 4th gear. |
| • | High line pressure |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | Using a scan tool can clear history DTCs. |
Diagnostic Aids
| • | Inspect for intermittent input speed sensor or output speed sensor circuit problems. |
| • | Inspect for possible incorrect calibration. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 | Visually inspect the transaxle cooling system for fluid leaks. Was the condition found and corrected? | -- | Go to Step 7 | Go to Step 3 |
3 | Has the transaxle fluid checking procedure been performed? | -- | Go to Step 4 | |
4 |
Does commanded gear ratio match ranges as shown? | 1st = 2.719 2nd = 1.487 3rd = 1.000 4th = 0.717 | Go to Diagnostic Aids | Go to Step 5 |
5 | Perform a line pressure inspection. Was the condition found and corrected? | -- | Go to Step 7 | Go to Step 6 |
6 | Inspect for possible clutch slippage. Was the condition found and corrected? | -- | Go to Step 7 | -- |
7 |
Has the last test failed or is the current DTC displayed? | -- | Go to Step 8 | System OK |
8 | Replace the transaxle assembly. Refer to Transmission Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Has the last test failed or is the current DTC displayed? | -- | Go to Step 2 | System OK |
