The powertrain control module (PCM) calculates the gear ratio based on the automatic transmission input (shaft) speed sensor (ISS) and output (shaft) speed sensor (OSS) readings. The PCM compares the known transmission gear ratio to the calculated ratio for the selected gear ranges. Refer to Range Reference .
If the PCM detects an unknown transmission gear ratio, then DTC P0730 sets. DTC P0730 is a type C DTC.
The following conditions are met for 10 seconds.
• | The system voltage is 8.0-18.0 volts. |
• | No MAP sensor DTCs P0106, P0107, or P0108. |
• | No TP sensor DTCs P0121, P0122, or P0123. |
• | No AT OSS DTCs P0502 or P0503. |
• | No AT ISS DTCs P0716 or P0717. |
• | No TFP manual valve position switch DTC P1810. |
• | The vehicle speed is greater than 8 km/h (5 mph). |
• | The TP angle is greater than 15%. |
• | The TFT is greater than 20°C (68°F). |
• | No gear range change for greater than 6.0 seconds. |
• | The engine torque is 110 N·m (80 lb ft) to 881 N·m (650 lb ft). |
• | The engine is running greater than 400 RPM for 7 seconds and not in fuel cutoff. |
• | The engine is running longer than 7 seconds. |
• | The Gear Ratio is one of the following: |
- | Greater than 2.51 or less than 2.44 |
- | Greater than 1.50 or less than 1.44 |
- | Greater than 1.03 or less than 0.97 |
- | Greater than 2.12 or less than 2.05 |
• | The PCM does not illuminate the malfunction indicator lamp (MIL). |
• | The PCM commands maximum line pressure. |
• | The PCM freezes shift adapts. |
• | 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 P0730 in PCM history. |
• | A scan tool clears the DTC from PCM history. |
• | 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 ignition switch is OFF long enough in order to power down the PCM. |
• | DTC P0730 defaults to an elevated line pressure condition which may result in TCC partial apply. This may induce idle surge and engine stall. |
• | A false or incorrect OSS or ISS signal can set DTC P0730. |
• | DTC P1870 detects an incorrect gear ratio in fourth gear with TCC applied. |
• | Inspect for any improperly installed after-market equipment. |
• | Sticking or contamination of shift valves may cause intermittent incorrect gear ratios. |
• | Refer to the Shift Solenoid Valve State and Gear Ratio table. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests the indicated range signal to the actual selected range. A faulty TFP manual valve position switch could set DTC P1810.
This step tests for proper ratios in each commanded gear state.
Step | Action | Value(s) | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Diagnostic System Check - Engine Controls in Engine Controls | |||||||||||||
2 | Perform the Transmission Fluid Checking Procedure. Refer to Transmission Fluid Check . Is the procedure complete? | -- | Go to Transmission Fluid Check | |||||||||||||
Important: Before clearing the DTCs, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the PCM. Refer to Transmission Fluid Pressure Manual Valve Position Switch Logic . Does the scan tool TFP switch A/B/C display match each selected gear range? | -- | Go to DTC P1810 | ||||||||||||||
Are the commanded gear ratios within the values for each specified gear range? | Rev: 2.04-2.12 1st: 2.42-2.50 2nd: 1.44-1.50 3rd: 0.25-1.03 | Go to Diagnostic Aids | ||||||||||||||
5 |
Refer to the Line Pressure Check . Is the line pressure within specifications for each selected gear range? | -- | ||||||||||||||
6 |
Refer to Automatic Transmission Fluid and Filter Replacement . Was excessive contamination found? | -- | Go to Transmission Overhaul in Transmission Unit Repair Manual | |||||||||||||
7 | Inspect the transmission for the following conditions:
Did you find and correct the condition? | -- | Go to Transmission Overhaul in Transmission Unit Repair Manual | |||||||||||||
8 | Is the system line pressure low only in the specific gear which indicated an incorrect gear ratio? | -- | ||||||||||||||
9 | Inspect for fluid pressure loss in the following areas:
Did you find and correct the condition? | -- | Go to Transmission Overhaul in Transmission Unit Repair Manual | |||||||||||||
10 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
The powertrain control module (PCM) calculates a ratio based on the automatic transmission input shaft speed (ISS) sensor and output shaft speed (OSS) sensor readings. The PCM compares the known transmission gear ratio to the calculated ratio, for the selected gear range.
If the PCM detects an incorrect gear ratio, then DTC P0730 sets. DTC P0730 is a type C DTC.
• | No MAP DTCs P0106, P0107, P0108. |
• | No AT ISS sensor DTCs P0716 or P0717. |
• | No AT OSS sensor DTCs P0722 or P0723. |
• | No TFP manual valve position switch DTC P1810. |
• | The vehicle speed is greater than 6.4 km/h (4 mph). |
• | The APP angle is greater than 15%. |
• | The TFT is greater than 20°C (68°F). |
• | System voltage is 8.0-18.0 volts. |
• | 10 seconds must have elapsed since the last gear range change. |
• | The engine speed is greater than 475 RPM for at least 7 seconds. |
• | The engine speed is less than 3750 RPM. |
• | The engine torque is 100-642 N·m (80-475 lb ft). |
• | All the conditions for Running the DTC are met for 7 seconds. |
• | The Gear Ratio is one of the following: |
- | Greater than 2.52 or less than 2.42 |
- | Greater than 1.50 or less than 1.45 |
- | Greater than 1.02 or less than 0.98 |
- | Greater than 0.77 or less than 0.73 |
- | Greater than 2.12 or less than 2.04 |
• | The PCM does not illuminate the malfunction indicator lamp (MIL). |
• | The PCM commands maximum line pressure. |
• | The PCM freezes shift adapts. |
• | The PCM stores DTC P0730 in PCM history. |
• | A scan tool clears the DTC from PCM history. |
• | 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 ignition switch is OFF long enough in order to power down the PCM. |
• | First, diagnose and clear any engine DTCs that are present. Then inspect for any transmission DTCs that may have reset. If a DTC P0717 and a DTC P0730 are both present, diagnose DTC P0717 first. |
• | DTC P0730 defaults to an elevated line pressure condition which may result in TCC partial apply. This may induce idle surge and engine stall. |
• | Sticking or contaminated shift valves may cause an undefined gear ratio. |
• | Refer to the Shift Solenoid Valve State and Gear Ratio table and the Range Reference table. |
• | DTC P1870 detects an incorrect gear ratio in fourth gear with TCC applied. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests the indicated range signal to the actual selected range. A faulty TFP manual valve position switch could set DTC P0730.
This step tests for proper ratios in each commanded gear state.
Step | Action | Value(s) | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Diagnostic System Check - Engine Controls in Engine Controls | |||||||||||||
2 | Perform the Transmission Fluid Checking Procedure. Refer to Transmission Fluid Check . Is the Transmission Fluid Checking Procedure complete? | -- | 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. Refer to Transmission Fluid Pressure Manual Valve Position Switch Logic . Does the scan tool TFP Switch A/B/C display match each selected gear range? | -- | Go to DTC P1810 | ||||||||||||||
Are the gear ratios within the parameters for each specified gear range? | Rev: 2.04-2.12 1st: 2.42-2.52 2nd: 1.45-1.50 3rd: 0.98-1.02 4th: 0.73-0.77 | Go to Diagnostic Aids | ||||||||||||||
5 |
Refer to Line Pressure Check . Is the line pressure within specifications for each selected gear range? | -- | ||||||||||||||
6 |
Refer to Automatic Transmission Fluid and Filter Replacement . Was excessive contamination found? | -- | Go to Transmission Overhaul in Transmission Unit Repair Manual | |||||||||||||
7 | Inspect the transmission for the following conditions:
Was the condition found? | -- | Go to Transmission Overhaul in Transmission Unit Repair Manual | |||||||||||||
8 | Is the system line pressure low only in the specific gear which indicated an incorrect gear ratio? | -- | ||||||||||||||
9 | Inspect for fluid pressure loss in the following areas:
Was the condition found? | -- | Go to Transmission Overhaul in Transmission Unit Repair Manual | |||||||||||||
10 |
Refer to Transmission Fluid Check . Important: The Clear TAPS function will clear all adapt cells. This may affect transmission performance. The PCM will update the transmission adapt cell values as the vehicle is driven. Did you complete the above procedure? | -- | -- | |||||||||||||
11 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |