Code 3-1-1 (Speedometer Signal)
Turn ignition off. Remove panel under instrument panel on driver side. Disconnect 12-pin connector from speedometer. Connect an ohmmeter between Blue/Black wire of speedometer connector and terminal No. 34 (Blue/Black wire) of fuel system ECU. Resistance should be zero ohms. If resistance is present, check wiring and connectors. If problem persists, check speedometer operation and related wiring.