Engine Controls - Tests W/codes: Other Lexus LX J80

TWO-TRIP DETECTION LOGIC

When a malfunction initially occurs, Diagnostic Trouble Code (DTC) will be temporarily stored in ECM memory, but MIL on instrument panel will not illuminate. The second time malfunction is detected, MIL on instrument panel will illuminate, provided ignition is turned off and then back on after first malfunction was detected. This is referred to as the 2-Trip Detection Logic and only applies to specific DTCs.

Note. When road testing vehicle in CHECK mode (Toyota scan tester only), the Two Trip Detection Logic will not function. Also, MIL will illuminate first time a malfunction is detected.

DATA LINK CONNECTOR

OBD-II regulations (SAE J-1850) standardizes Data Link Connector (DLC) configurations. See DATA LINK CONNECTOR NO . 3 (DLC3) LOCATION table.

DATA LINK CONNECTOR NO. 3 (DLC3) LOCATION

FREEZE-FRAME DATA

OBD-II or Toyota scan tester can by used to check freeze-frame data. The ECM records engine operating condition when a misfire, fuel trim (mixture) malfunction or other malfunction (fuel system, calculated load, coolant temperature, fuel trim (mixture), engine speed, vehicle speed, etc.) exists. If more than one fault is detected, only data from the first malfunction is recorded. Recorded data is useful for determining conditions in which the malfunction occurs.

NORMAL Mode Code Retrieval

1. Connect scan tester to Data Link Connector No. 3 (DLC3). Turn ignition on with engine off. Turn scan tester on. Using scan tester manufacturer's instructions, check for DTCs and freeze-frame data.
2. If scan tester displays UNABLE TO CONNECT TO VEHICLE, DLC3 must be checked. See «DLC3 INSPECTION»(ref-21947-S03578759232001010300000) under SCAN TESTER PROBLEMS. If scan tester does not display UNABLE TO CONNECT TO VEHICLE, go to next step.
3. Record any DTCs and freeze-frame data displayed for system diagnosis. If driveability problem exists and no DTCs are present, go to TESTS W/O CODES article for diagnosis by symptom.
4. If any DTCs are present, perform appropriate circuit test. See «TROUBLE CODE IDENTIFICATION»(ref-21947-S05787691322001010300000) table. For more information on freeze-frame data, see «FREEZE-FRAME DATA»(ref-21947-S39919248702001010300000) under INTRODUCTION. For information on 2-trip detection logic codes, see «TWO-TRIP DETECTION LOGIC»(ref-21947-S13207772632001010300000) under INTRODUCTION.
5. After repairs for DTC have been completed, DTCs must be cleared from ECM memory. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-21947-S42318431212001010300000) .

CHECK Mode Code Retrieval (Toyota Scan Tester Only)

1. Ensure vehicle battery is fully charged. Apply parking brake. Shift transmission/transaxle into Neutral (M/T) or Park (A/T). Turn A/C and all accessories off. Ensure throttle is in idle position.
2. Turn ignition off. Connect scan tester to Data Link Connector No. 3 (DLC3). See «DATA LINK CONNECTOR»(ref-21947-S25729409192001010300000) . Turn ignition on with engine off. Turn scan tester on.
3. Switch scan tester from NORMAL mode to CHECK mode. CHECK mode is operational if MIL on instrument cluster flashes. Start engine. Ensure MIL goes off. Try to simulate conditions of driveability complaint described by customer. NOTE: If ignition switch is turned from ON to ACC or OFF position, all DTCs and freeze-frame data will be erased. DO NOT switch modes until all DTCs and freeze-frame data are recorded.
4. Record any DTCs and freeze-frame data displayed for system diagnosis. If driveability problem exists and no codes are present, go to TESTS W/O CODES article for diagnosis by symptom.
5. If any DTCs are present, perform appropriate circuit test. See «TROUBLE CODE IDENTIFICATION»(ref-21947-S05787691322001010300000) table. For more information on freeze-frame data, see «FREEZE-FRAME DATA»(ref-21947-S39919248702001010300000) . For information on 2-trip detection logic codes, see «TWO-TRIP DETECTION LOGIC»(ref-21947-S13207772632001010300000) .
6. After repairs for DTC have been completed, DTC must be cleared from ECM memory. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-21947-S42318431212001010300000) .

CIRCUIT TESTS

Note. For component location, see appropriate illustration in THEORY/OPERATION article.

Condition

Following conditions continue with engine speed of 900 RPM or less

1. Closed throttle position switch in ON position.
2. MAF sensor output is 2.2 volts or less.

DTC is set when ECT sensor temperature is 86°F (30°C) or less for at least 20 minutes of engine operation. Possible causes are

1. Engine Coolant Temperature (ECT) sensor.
2. Cooling system.

DTC is set when ECM consistently detects more than 2 volts from VTA circuit and closed throttle position switch is on. Possible cause is

1. Throttle Position (TP) sensor.

DTC P0130 is set when sensor No. 1 voltage remains at .40-.55 volt during idle, once engine is at normal operating temperature. Possible causes are

1. Heated oxygen sensor.
2. Fuel trim.

Note. Oxygen sensor located in front of catalytic converter is referred to as sensor No. 1. Oxygen sensor located behind catalytic converter is referred to as sensor No. 2.

DTC is set when ECM detects a response time of one second or more from sensor to change from rich to lean, or lean to rich. Possible cause is

1. Heated oxygen sensor.

Note. Oxygen sensor located in front of catalytic converter is referred to as sensor No. 1. Oxygen sensor located behind catalytic converter is referred to as sensor No. 2.

DTC is set when either of the following conditions is present

1. Sensor heater current draw exceeds 2 amps.
2. Sensor heater current draw is .25 amp or less.

Possible causes are

1. Heated oxygen sensor open or short circuit.
2. Heated oxygen sensor heater.
3. ECM.

Note. Oxygen sensor located in front of catalytic converter is referred to as sensor No. 1. Oxygen sensor located behind catalytic converter is referred to as sensor No. 2.

DTC is set when sensor No. 2 voltage remains at .40-.55 volt during vehicle operation (25 MPH or more), once engine is at normal operating temperature. Possible cause is

1. Heated oxygen sensor.

Note. Oxygen sensor located in front of catalytic converter is referred to as sensor No. 1. Oxygen sensor located behind catalytic converter is referred to as sensor No. 2.

DTCS P0301-P0306 - CYLINDERS NO. 1-6 MISFIRE DETECTED

Note. When 2 or more codes for a misfiring cylinder are recorded repeatedly, but DTC P0300 is not recorded, it indicates that misfires were detected and stored into ECM memory at different times.

Two conditions can cause code to set. These are

1. During any particular 200 revolutions of engine, misfiring is detected which can cause catalytic converter overheating and/or damage.
2. During any particular 1000 revolutions of engine, misfiring is detected which can cause a deterioration in emission levels.

For possible causes, see DTC P0300 - RANDOM MISFIRE DETECTED circuit test.

1. PNP switch short circuit.
2. PNP switch.
3. ECM.

Note. Toyota scan tester can be used to confirm PNP switch.