GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2006 🢒 VUE - AWD 🢒 DTC 🢒 DTC P0731

Circuit Description

While driving in 1st gear, line pressure is supplied to the 1st clutch piston, the 1st clutch engages and the shaft and 1st gear rotate together to transmit drive force. The oil pressure is supplied to the 1st clutch via the suction filter, oil pump, main regulator, manual valve, shift valve, feed pipe and clutch piston. The powertrain control module (PCM) calculates the automatic transmission input shaft speed (AT ISS) sensor to automatic transmission output shaft speed (AT OSS) sensor ratio.

When the PCM detects an incorrect calculated ratio for 1st gear, while the PCM is commanding 1st gear, DTC P0731 sets. DTC P0731 is a type C DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0731 Incorrect 1st Gear Ratio

Conditions for Running the DTC
    • No ECT DTCs P0116, P0117, or P0118.
    • No TP DTCs P0122, P0123, P0222, or P0223.
    • No VSS DTCs P0501, P0502, or P0503.
    • No TR Switch DTCs P0705 or P0706.
    • No AT ISS DTCs P0716, P0717, or P0718.
    • No Clutch PC Performance DTCs P0746, P0747, P0776, or P0777.
    • No SS Valve Performance DTCs P0751, P0752, P0756, P0761, P0757, or P0762.
    • No Incorrect Shift Pattern DTC P0780.
    • No Clutch PC Solenoid Electrical DTCs P0962 or P0963.
    • No Clutch PC Solenoid 2 DTCs P0966 or P0967.
    • No SS 1 DTCs P0973 or P0974.
    • No SS 2 DTCs P0976 or P0977.
    • No SS 3 DTCs P0979 or P0980.
    • No TAC DTCs P2101, P2108, or P2553.
    • No APP DTC P2122, P2123, P2127, P2128, P2135, or P2138.
    • No Minimum Idle Position DTC P2176.
    • No TCC PC Solenoid DTCs P2763 or P2764.
    • No TCC Enable Solenoid DTCs P2769 or P2770.
    • No TAC Communication DTC U0107.
    • The system voltage is 11 volts or greater.
    • The vehicle speed is 2 km/h (1 mph)-12 km/h (8 mph).
    • The engine speed is 1,000 RPM or greater.
    • The transmission is in D, I, or L range.

Conditions for Setting the DTC
    • The actual gear ratio is 1.2 times greater than, or 0.75 times less than the known 1st gear ratio for 12 seconds or greater.
    • The vehicle speed calculated from mainshaft speed sensor is more than 11 km/h (7 mph) while the vehicle speed calculated from the output shaft speed sensor is less than 2 km/h (1 mph) for 3 seconds or more.
    • The actual gear ratio is correct to the known gear ratio for 3 seconds or more.

Action Taken When the DTC Sets
    • The PCM does not illuminate the malfunction indicator lamp (MIL) .
    • The PCM illuminates the service vehicle soon (SVS) lamp during the second consecutive trip in which the Conditions for Setting the DTC are met.
    • 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 P0731 in PCM history.

Conditions for Clearing the SVS Lamp/DTC
    • The PCM turns OFF the SVS lamp when the condition no longer exists.
    • A scan tool can clear the SVS lamp/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.

Diagnostic Aids
    • Inspect for a shift control system malfunction.
    • Inspect for a worn 1st clutch.
    • Inspect for an insufficient automatic transmission fluid pump output.

Test Description

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

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

    2.

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

    3.

  3. This step tests for low line pressure.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Visually inspect the transmission cooling system for fluid leaks.
  2. Repair any leaks as necessary. Refer to Fluid Leak Diagnosis .

Did you find and correct a condition?

--

Go to Step 8

Go to Step 3

3

Did you perform the Transmission Fluid Checking Procedure?

--

Go to Step 4

Go to Transmission Fluid Check

4

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.

    3. 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.

  3. Record the DTC Failure Records.
  4. Clear the DTC.
  5. Use the scan tool snapshot mode in order to record Gear Ratio and Gear Slip Ratio.
  6. Drive the vehicle in 1st gear, with the TP greater than 10%, and the vehicle speed greater than 12 km/h (8 mph) for 20 seconds or greater.
  7. Record the Gear Ratio and Gear Slip Ratio.

Is the Gear Slip Ratio within the specified range?

1.2:1-0.75:1

Go to Diagnostic Aids

Go to Step 5

5

Did you perform the Line Pressure Check Procedure?

--

Go to Step 6

Go to Line Pressure Check

6
  1. Inspect the 1st clutch plates for the following conditions:
    2. • Slipping
    • Dragging
    • Damage
  2. Repair any of the above items as necessary.

Did you complete the repair?

--

Go to Step 7

--

7
  1. Change the transmission fluid and filter. Refer to Transmission Fluid Replacement .
  2. Inspect the transmission fluid for the correct level.
  3. Add new fluid as necessary.

Did you complete the above procedures?

--

Go to Step 8

--

8

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Drive the vehicle in 1st gear, with the throttle greater than 10%, in order to obtain a gear slip ratio of 1.2:1-0.75:1 for 20 seconds.
  4. Select Specific DTC.
  5. Enter DTC P0731.

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

System OK