ECM/PCM Idle Learn Procedure

ECM Idle Learn Procedure

The idle learn procedure must be done so that the ECM can learn the engine idle characteristics. Do the idle learn procedure whenever you do any of these actions:
- Disconnect the battery.
- Replace the ECM or disconnect its connector.
- Reset the ECM.

NOTE: Erasing DTCs with HDS does requires the idle learn procedure to be done again.

- Remove the No. 6 ECU (ECM) (15 A) fuse from the under-dash fuse/relay box.
- Remove the No. 41 BATTERY (100 A) fuse from the under-hood fuse/relay box.
- Remove the PGM-FI main relay.
- Remove the battery wire from the under-hood fuse/relay box.
- Disconnect any of the connectors from the under-hood fuse/relay box.
- Disconnect the connector (C404) between the dashboard wire harness A and dashboard wire harness B.
- Disconnect the G1 terminal.
- Adjust the idle speed.

To complete the idle learn procedure do this:

1. Make sure all electrical items (A/C, audio, rear window defogger, lights, etc.) are turned off.
2. Start the engine. Hold the engine speed at 3,000 rpm with no load (in neutral) until the radiator fan comes on, or the engine coolant temperature reaches 176 °F (80 °C) -212 °F (100 °C).
3. Let the engine idle for about 5 minutes with the throttle fully closed and with all electrical items off.

NOTE: If the radiator fan comes on during this step, the time when it is operating must not be included in the 5 minutes.