For 1990-2009 cars

### Removal Procedure

Important:

• | When returning a replaced control unit, do not clear the fault memory.

• | The security code must be reset using Tech 2 when replacing or interchanging the engine control module (before removal).

1. Open the hood.
2. Read out control unit data with a Tech 2. Refer to Diagnostic System Check - Vehicle .

Caution: Refer to Battery Disconnect Caution in the Preface section.

Important: The battery must not be disconnected until all consumers (e.g. fan) have ceased operation. However, a minimum waiting time of 30 seconds must be observed.

3. Disconnect the battery.

• | Remove the ground connection from the ground terminal.

• | Loosen the nut.

4. Remove the wiring harness from the engine control module (ECM).

Disconnect the 2 wiring harness plugs (1).

5. Remove the ground cable (2) from the ECM.

Remove the bolt.

6. Remove the ECM.

Remove the 4 bolts (3).

### Installation Procedure

Notice: Refer to Fastener Notice in the Preface section.

1. Install the ECM.

Tighten
Tighten the 4 bolts to 8 N·m (71 lb in).

2. Install the ground cable to the ECM.

Tighten
Tighten the bolt to 8 N·m (71 lb in).

3. Install the wiring harness to the ECM.

Connect the 2 wiring harness plugs.

4. Connect the battery.

Install the ground connection to the ground terminal.

Tighten
Tighten the nut to 5 N·m (44 lb in).

5. Upload the control unit data with Tech 2. Refer to Diagnostic System Check - Vehicle .
6. For programming procedures, refer to Control Module References .
7. Close the hood.