Code 3-1-2 (Knock/Fuel Enrichment)

Turn ignition on. Connect a voltmeter between terminal No. 28 (Brown wire on 240 series and Green/Red wire on 740 GL) of fuel system ECU connector and ground. Reading should be approximately 0.7 volt. If voltage is not specified, check resistance between appropriate ECU connector wire and knock sensor. For knock sensor testing, see procedures in SYSTEM/COMPONENT TESTS article.