For 1990-2009 cars

### Circuit Description

The TCM uses engine speed, transmission output speed, TCC status, and current gear in order to determine if excessive component slippage is occurring.

When the TCM detects an increase in RPM for a particular gear above a predetermined amount, then DTC P0730 sets. DTC P0730 is a type B DTC.

### Conditions for Running the DTC

• | The engine is running.

• | The gear position is not P, R, N.

• | The transmission is not in safety mode.

• | The enabling conditions for DTC P0757 fail case 1 are not met.

All the above conditions are met plus one of the following conditions:

#### Condition 1

The engine speed has not exceeded 3488 RPM.

#### Condition 2

Engine and transmission output speed has not exceeded 2976 RPM in 3rd gear.

### Conditions for Setting the DTC

#### Condition 1

Absolute slippage that is calculated by the TCM is greater than the following predetermined amount:

• | Commanded gear is 1st and the transmission output speed is greater than 352 RPM for 4.0 seconds.

• | Commanded gear is 2nd and the transmission output speed is greater than 576 RPM for 4.0 seconds.

• | Commanded gear is 3rd and the transmission output speed is greater than 896 RPM for 4.0 seconds.

• | Commanded gear is 4th and the transmission output speed is greater than 1216 RPM for 4.0 seconds.

#### Condition 2

Engine and transmission output speed is less than 992 RPM in 3rd gear for 4.0 seconds.

### Action Taken When the DTC Sets

• | Early production - The TCM illuminates the service transmission lamp (STL) and sends a MIL request to the ECM on the second consecutive drive trip that the diagnostic runs and fails. The ECM then illuminates the MIL.

• | Late production - The TCM flashes the Sport Mode Lamp and sends a MIL request on the second consecutive drive trip that the diagnostic runs and fails. The TCM then illuminates the MIL.

• | The ECM records the operating conditions in the Freeze Frame at the time of the MIL request from the TCM.

• | The transmission operates in the default mode (maximum line pressure, command 4th gear, inhibit TCC, freeze shift adapts).

### Conditions for Clearing the MIL/DTC

• | Early production - The TCM turns off the STL as soon as the fault is no longer present.

• | Late production - The TCM stops flashing the sport mode lamp as soon as the fault is no longer present.

• | The ECM turns off the MIL after three consecutive drive trips during which the TCM sends no MIL request.

• | A History DTC clears after forty consecutive warm-up cycles, if no failures are present by this diagnostic or any other emission related diagnostic.

• | The scan tool clears the MIL/DTC.

• | The TCM cancels the DTC default mode actions when the fault no longer exists and the ignition switch is Off long enough in order to power down the TCM.

### Diagnostic Aids

• | Vehicles equipped with Fuel Cap Lamps utilize the Sport Mode lamp to indicate a transmission malfunction. In these vehicles, the Sport Mode Lamp flashes at 200 millisecond intervals when the TCM commands the lamp ON.

• | Vehicles not equipped with Fuel Cap Lamps are equipped with a dedicated Service Transmission Lamp (STL) on the Instrument Panel Cluster (IPC). The STL illuminates steadily when the TCM commands the lamp ON.

• | A DTC P0722 could cause DTC P0730 to set falsely.

• | Inspect for intermittent automatic transmission output (shaft) speed sensor (A/T OSS) circuit conditions.

• | Sticking or contamination of shift valves may cause intermittent incorrect gear ratios.

### Test Description

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

1. A condition in the Output Speed Sensor Circuit can cause this DTC to set. Perform that diagnostic procedure first.

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

3. This step verifies that the correct output speeds occur for commanded gears.

4. This step tests for low line pressure.

#### DTC P0730 Incorrect Gear Ratio

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to On-Board Diagnostic System Check
2 | Is DTC P0722 also set? | -- | Go to DTC P0722 Output Speed Sensor Circuit Low Input | Go to Step 3
3 | Perform the Transmission Fluid Checking Procedure. Refer to Transmission Fluid Check . Is the procedure complete? | -- | Go to Step 4 | Go to Transmission Fluid Check
4 |

1. Install the Scan Tool .
2. With the engine OFF, turn the ignition switch to the RUN position.

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 ECM/TCM.

3. Record the DTC Failure Records.
4. Clear the DTCs.
5. Start the engine.
6. Place the Shift Selector in D4.
7. Drive the vehicle above 7 mph for greater than 3 seconds in each specified gear range.
8. Use the Scan Tool Snapshot Mode in order to record the transmission output speed RPM for each commanded gear range: 1st, 2nd, 3rd and 4th.

Are the commanded gear output speed RPMs greater than the values for each specified gear range?

1st: 352 RPM

2nd: 576 RPM

3rd: 896 RPM

4th: 1216 RPM

Go to Step 5

Go to diagnostic aids

5 |

1. Connect the J 21867 pressure gauge to the transmission line pressure tap.
2. Perform the Line Pressure Check Procedure.

Refer to the Line Pressure Check .

Is the line pressure within specifications for each selected gear range?

--

Go to Step 6

Go to Step 8

6 |

1. Remove the main case oil pan.

Refer to Changing Fluid and Oil Filter .

2. Inspect the oil pan and the fluid for contamination.

Was excessive contamination found?

--

Go to Unit Repair

Go to Step 7

7 | Inspect the transmission for the following conditions:

• | Sticking shift valves

• | Stuck apply pistons

Was the condition found?

--

Go to Step 10

Go to Unit Repair

8 | Is the system line pressure low only in the specific gear which indicated an incorrect Output Speed? | -- | Go to Step 9 | Go to Symptom Diagnosis Low Line Pressure
9 | Inspect for fluid pressure loss in the following areas:

• | 1-2/3-4 SS valve seal

• | 2-3 SS valve seal

• | Valve body passages

• | Valve body gaskets

• | Band apply pistons and seals

• | Clutch apply pistons and seals.

Was the condition found?

--

Go to Step 10

Go to Unit Repair

10 | Perform the following procedure in order to verify the repair:

1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle in D4.
4. Use the Scan Tool Snapshot Mode in order to record the transmission Output Speed RPM for each commanded gear range: 1st, 2nd, 3rd, and 4th.

Are the commanded gear output speed RPMs lower than the values for each of the specified gears?

1st: 352 RPM

2nd: 576 RPM

3rd: 896 RPM

4th: 1216 RPM

System OK

Go to Step 1