2002 MY OBD-II System Operation Summary - MotorCraftService.com

HO2S MonitorFront HO2S SignalThe time between HO2S switches is monitored after vehicle startup and during closed loop fuel conditions.Excessive time between switches or no switches since startup indicate a malfunction. Since “lack of switching”malfunctions can be caused by HO2S sensor malfunctions or by shifts in the fuel system, DTCs are stored thatprovide additional information for the “lack of switching” malfunction. Different DTCs indicate whether the sensorwas always indicates lean/disconnected (P1131 P1151), always indicates rich (P1132 P1152), or stoppedswitching due to excessive long term fuel trim corrections (P1130 P1150, Note: these DTCs are being phased outof production). Most 2002 MY vehicles will no longer require part throttle operation to run the lack of switching test– lack of switching codes may be set at idle.Most 2002 MY vehicles will monitor the HO2S signal for high voltage, in excess of 1.5 volts and store a uniqueDTC. (P0132 P0152). An over voltage condition is caused by a HO2S heater or battery power short to the HO2Ssignal line.HO2S “Lack of Switching” Operation:DTCs P1130 Lack of switching, fuel trim at clip, Bank 1P1131 Lack of switching, sensor indicates lean, Bank 1P1132 Lack of switching, sensor indicates rich, Bank 1P0132 Over voltage, Bank 1P1150 Lack of switching, fuel trim at clip, Bank 2P1151 Lack of switching, sensor indicates lean, Bank 2P1152 Lack of switching, sensor indicates rich, Bank 2P0152 Over voltage, Bank 2Monitor executionMonitor SequenceSensors OKMonitoring Durationcontinuous, from startup and while in closed loop fuelNoneTP, MAF, ECT, IAT, FTP30 to 60 seconds to register a malfunctionTypical HO2S “Lack of Switching” entry conditions:Entry condition Minimum MaximumClosed Loop RequestedEngine Load 20% 60%Time since engine start-upInferred Exhaust Temperature180 seconds800 o FTypical HO2S “Lack of Switching” malfunction thresholds:< 5 switches since startup after 30 seconds in test conditions> 60 seconds since last switch while closed loop> 30 seconds since last switch while closed loop at Short Term Fuel Trim limitFORD MOTOR COMPANY REVISION DATE: OCTOBER 02, 2001 PAGE 24 OF 66