Without Scan Tool

When the test connector (blue, 1-pin turbo; green, 1-pin non-turbo) is grounded, the hold indicator light (turbo) or MIL (non-turbo) flashes any service codes stored in control unit memory. If more than one code is present, they are displayed in numerical order, lowest number first.

The turbo test connector is located beneath the dash, left of steering column.

The non-turbo test connector is in the engine compartment near the left side wheel housing.