Code 3-1-1 (Speedometer Signal)

Turn ignition off. Remove panel under instrument panel on driver's side. Disconnect 12-pin connector from speedometer. On 240 and 240 DL, connect an ohmmeter between Blue/Black wire of speedometer connector and terminal No. 34 (Blue/Black wire) of fuel system ECU. On 740 GL, connect ohmmeter between Violet/White wire of speedometer connector and terminal No. 34 (Violet/White 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.