For 1990-2009 cars

## Diagnostic System Check - Automatic Transmission 2.2L

### Circuit Description

The Diagnostic System Check-Automatic Transmission is an organized approach to identify a condition created by an automatic transmission. The Diagnostic System check is the diagnostic starting point for an automatic transmission concern. The Diagnostic System Check directs you to the next logical step for diagnosing a transmission concern. Perform this check only if there is a driveability concern or if you have been directed here from another service information section.

Follow the table to help reduce diagnostic time and help prevent unnecessary replacement of good parts.

### Diagnostic Aids

Important:

• | Do not clear the DTC unless directed by a diagnostic procedure. Clearing the DTC will erase all Freeze Frame and Failure Records stored in PCM memory.

• | Poor engine performance can sometimes be diagnosed as a transmission driveability condition. In order to avoid misdiagnosis of the automatic transmission, always perform Diagnostic System Check - Engine Controls in Engine Controls -2.2L (L61).

• | Use a scan tool that is known to function correctly. If necessary, test the scan tool on another vehicle.

• | Ensure the scan tool contains the most current file available.

• | The scan tool will display a loss of communication error message under the following conditions:

- | PCM power is interrupted

- | The ignition switch is turned OFF

- | The battery voltage level is very low

- | A poor connection at the diagnostic link connector (DLC)

### Test Description

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

1. This step determines if the scan tool is receiving power through the DLC connector.

2. The MIL should illuminate whenever the ignition is ON and the engine is not running.

3. This step determines if the PCM is transmitting class 2 serial data to the DLC and that the class 2 data circuit is not open or shorted.

4. This step determines if a DTC is current or stored in history.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Install a scan tool.

Important:

• | Check for applicable service bulletins before proceeding with this test. Perform this test only if there is a driveability complaint or if you have been directed to this table from another section in the service information.

• | Do not turn the ignition OFF when performing this diagnostic procedure. Do not clear the DTCs unless instructed by this diagnostic procedure.

2. Turn ON the ignition, with the engine OFF.

Does the scan tool turn ON?

--

Go to Step 2

Go to Diagnostic Starting Point - Data Link Communications in Data Link Communications

2 | Is the MIL ON? | -- | Go to Step 3 | Go to Malfunction Indicator Lamp (MIL) Inoperative in Engine Controls - 2.2L (L61)
3 | Attempt to establish communication with the PCM. Does the scan tool communicate with the PCM? | -- | Go to Step 4 | Go to Diagnostic Starting Point - Data Link Communications in Data Link Communications
4 | Important: Diagnostic Trouble Codes (DTCs), engine performance, and transmission default actions can greatly affect the transmission performance. Ensure that these items are not the cause of a transmission concern. Use the scan tool Capture Info function in order to save or capture, Store Info, any DTC Information.

Are there any DTCs present?

--

Go to Diagnostic Trouble Code (DTC) List/Type

Go to Symptoms - Automatic Transmission

## Diagnostic System Check - Automatic Transmission 3.0L

### Description

Important: Do not perform the Diagnostic System Check-Automatic Transmission unless one of the concerns noted is present. Failure to follow this procedure could lead to misdiagnosis of the system.

The Diagnostic System Check-Automatic Transmission is an organized approach to identifying a condition created by an electronic transmission control system. The Diagnostic System Check-Automatic Transmission is intended for use in diagnosing a concern in a vehicle with separate engine and transmission control modules, ECM and TCM.

When an emission related diagnostic trouble code (DTC) sets as a result of a transmission fault, the TCM requests the ECM to illuminate the malfunction indicator lamp (MIL). This request will be identified by the ECM as DTC P0700. The ECM may also independently illuminate the MIL. Although either module may cause the MIL to illuminate, the scan tool can display DTCs from only one module at a time. In addition, the Clear DTC Info command clears DTC data from both modules. If the DTC failure records are not recorded from both modules before the DTC data is cleared, important diagnostic information will be erased.

Your training and experience as a technician may cause you to focus on either the TCM or the ECM, instead of both modules at the same time. To ensure that both modules are properly diagnosed, separate system checks are included. The Diagnostic System Check - Engine Controls in Engine Controls-3.0L (L81) identifies DTC status and communication function for the ECM. If no ECM DTCs are present, the Diagnostic System Check - Engine Controls in Engine Controls -3.0L (L81) will direct you to the Diagnostic System Check-Automatic Transmission.

The ECM diagnostics do not require transmission data in order to run. Correct use of the tables will reduce diagnostic time and prevent the replacement of good parts.

### Diagnostic Aids

Inspect all of the related wiring and connections including the connections at the TCM, as these may cause an intermittent concern. Inspect the terminals for any damage or any corrosion. Inspect the connector for any pushed-out terminals.

### Test Description

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

1. Do not perform the Diagnostic System Check - Automatic Transmission unless one of the concerns listed is present. Failure to follow this procedure could lead to misdiagnosis of the system.

2. Capturing the stored ECM information will preserve the data that will be lost upon instruction to clear the DTCs at the end of a diagnostic table, or if a TCM disconnect or replacement occurs during a diagnostic procedure. Write down any non emissions DTCs that are set at this time. Review the captured information at the end of the diagnostic table in order to catch the next DTC in the event that the multiple DTCs were stored. Follow the order of priority as listed below.

3. Check for applicable service bulletins before proceeding with the diagnosis.

4. If multiple DTCs are stored, diagnose the DTCs in the following order of priority:

1. | The System Voltage DTCs

2. | Component level DTCs

Diagnose the multiple DTCs within this category in numerical order starting with the lowest DTC number.

3. | The System level DTCs

4. | The Transmission DTCs

When there is a known exception, a DTC table may direct the technician to diagnose a different DTC first.

5. Compare the actual control system data with the values in the Transmission Scan Tool Data List in order to determine if any parameter is not within limits. A base engine condition, such as advanced cam timing, may substantially alter the sensor values. If the actual data does not correspond with the values in the Transmission Scan Tool Data List, but the corresponding DTC is not set, this indicates that you have to meet specific conditions before some diagnostics will run. This information is in the supporting text for the DTC table. If you suspect a system fault, such as Shift Solenoid operation, TCC operation, refer to the DTCs that apply to that system. The DTC tables are not, by design, for use unless a DTC is set; however, many tables begin with a functional test of the related component. This information can be a useful aid in diagnosis.

Step | Action | Value | Yes | No
--- | --- | --- | --- | ---
1 | Inspect for one or more of the following conditions:

• | The malfunction indicator lamp (MIL) illuminates with the engine running.

• | A "Service Vehicle" message is displayed in the driver information center.

• | There is a customer concern of powertrain performance/driveability.

• | There is a suspected fault in a powertrain controlled component or system.

Is one or more of the conditions present?

--

Go to Step 2

System OK

2 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 3 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 3.0L (L81)
3 | With the scan tool, select transmission data. Does the scan tool display transmission data? | -- | Go to Step 4 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
4 |

1. Inspect for applicable Service Bulletins which may address the concerns.
2. Perform repair procedures as necessary.

Did a Service Bulletin procedure correct the condition?

--

System OK

Go to Step 5

5 | With the scan tool, inspect for DTCs in the TCM. Are there any DTCs present? | -- | Go to Diagnostic Trouble Code (DTC) List/Type | Go to Step 6
6 | With the scan tool, compare the transmission data with the values shown in the Transmission Scan Tool Data List. Refer to Scan Tool Data List . Are the displayed values normal or within typical ranges? |  | Go to Symptoms - Automatic Transmission | Go to Transmission Component and System Description