Ignition ECU LED Flashing

The ignition ECU is capable of self-diagnosis, which enables it to identify malfunctions which could occur during operation. These malfunctions are displayed by a yellow LED located on the instrument cluster. The number of flashes usually identifies the specific component which is malfunctioning. Constant flashing of the LED associated with either a four or six flash code are in most cases due to intermittent poor electrical contact in the wiring terminals connecting the components. Once the ignition ECU has detected an intermittent electrical problem, the LED will remain in the constant flashing mode until the engine is turned off. Once the engine is restarted, the ECU will have cleared its memory of the intermittent malfunction. The following procedure should be followed prior to replacing any components, which in most cases are not the cause of the problem.

1. Locate the 9-pin blue connector (MC26) and 4-pin blue connector (MC27) at cowl panel on right side of brake fluid reservoir.
2. Disconnect both connectors and check that each individual terminal is fully locked into connector housing.
3. Apply electrical spray contact cleaner to both connector terminals.
4. Apply a small amount of electrical contact/anti corrosion grease to each individual wire terminal.
5. Connect each connector, then using a small screwdriver from the back of the connector, push in each individual terminal into the connector housing while holding the opposite wire. Repeat on opposite side of both connectors.
6. Ensure there is sufficient slack in wiring to prevent pulling on wire terminals.
7. Disconnect both detonation sensors, located in top of each cylinder head..
8. Disconnect No. 1 cylinder sensor, located on RH side of power steering reservoir.
9. Apply electrical spray contact cleaner to both connector terminals.
10. Apply a small amount of electrical grease on each individual terminal.
11. Reconnect electrical connectors and road test vehicle.