Engine Control System Self Diagnostics: Diagnosis Toyota Avalon XX20 рестайлинг

TESTING PROCEDURE

To ensure correct diagnosis and repair, testing should be done in the following sequence

1. Record Customer Complaint Ensure all customer complaints or observations are recorded. Test drive vehicle with customer when necessary for malfunction verification.
2. DLC3 Inspection Connect the OBD II scan tool or hand-held tester to DLC3. see scheme 1 If the display indicates a communication fault in the tool, inspect DLC3. See «DATA LINK CONNECTOR NO. 3 INSPECTION»(ref-151954-S05235473282003010900000) under SCAN TOOL PROBLEMS.
3. Retrieve DTCs & Freeze Frame Data Using Toyota hand-held tester or scan tool, retrieve diagnostic trouble codes (DTC) from engine control module (ECM) and record any freeze frame data (if applicable). See «RETRIEVING DIAGNOSTIC TROUBLE CODES»(ref-151954-S16372262862003010900000) and «FREEZE FRAME DATA»(ref-151954-S36387861832003010900000).
4. Clear DTCs & Freeze Frame Data Using Toyota hand-held tester or scan tool, clear DTCs and freeze frame data from ECM. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151954-S22549028572003010900000).
5. Visual Inspection Inspect all electrical connectors and wiring for suspected circuit or component. Ensure all electrical connections are clean and tight.
6. Check Mode Diagnosis Set the check mode diagnosis. See «TWO-TRIP DETECTION LOGIC»(ref-151954-S01870655182003010900000).
7. Confirm Symptoms If the engine does not start, perform steps 9 and 10 first. If a malfunction occurs, go to the next step. If a malfunction does not occur, simulate symptom. Perform road test. Determine if original symptoms still exist, then go to the next step.
8. DTC Check Check DTC. See «SYSTEM OVERVIEW»(ref-151954-S20682626362003010900000). If DTC is normal, go to the next step. If there is a malfunction code, go to step 11.
9. Basic Inspection Perform basic inspection. See «BASIC INSPECTION»(ref-151954-S24750319032003081200000). If results are OK, go to the next step. If results are not good, inspect parts, then go to step 13.
10. Determine Symptom If no DTCs are present and a driveability condition exists, diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.). See SYMPTOMS in appropriate «TROUBLE SHOOTING - NO CODES»(ref-151977) article. If circuits are OK, inspect parts and go to step 13. If circuits are not good, go to the next step.
11. Diagnose & Repair Diagnostic Trouble Codes For DTC descriptions, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151954-S06837564092003010900000). Perform appropriate DTC test. See «DIAGNOSTIC TESTS»(ref-151954-S35851798372003010900000). If no DTCs are present and a no start condition exists, proceed to appropriate «BASIC DIAGNOSTIC PROCEDURES - V6 & V8»(ref-151953) article. If results are OK, go to step 13. If the results are not good, go to the next step.
12. Intermittent Problem Check Check for intermittent problems. See «INTERMITTENT PROBLEMS CHECK (HAND-HELD TESTER ONLY)»(ref-151954-S11476329032003081200000).
13. Verification Procedure Identify problem and make necessary adjustments and repairs. After repairs have been completed, clear all DTCs from ECM. See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151954-S22549028572003010900000). Perform road test. Ensure no DTCs exist and all symptoms and/or complaints have been repaired.

MALFUNCTION INDICATOR LIGHT INSPECTION

Note. The malfunction indicator light (MIL) may also be referred to as CHECK ENGINE light. Inspect MIL to ensure it is operational and will come on if a diagnostic trouble code (DTC) is set.

1. The MIL comes on when the ignition switch is turned ON and the engine is not running. If the MIL does not light up, trouble shoot the combination meter. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.
2. When the engine started, the MIL should go off. If the lamp remains on, the diagnosis system has detected a malfunction or abnormality in the system. See «TESTING PROCEDURE»(ref-151954-S12346437822003010900000) .

NORMAL Mode DTC Retrieval

Note. If there is no DTC in the normal mode, check the 1st trip DTC using Continuous Test Results function (Mode 7 for SAE J1979) or the OBD II scan tool or hand-held tester.

Note. Hand-held tester only: When the diagnosis system is switched from the normal mode to the check mode, it erases all DTCs and freeze frame data recorded in the normal mode. So before switching modes, always check the DTC and freeze frame data and note them down.

Note. When simulating symptoms with an OBD II scan tool (excluding hand-held tester) to check the DTC, use the normal mode. For code on the DTC chart subject to 2 trip detection logic, perform either of the following actions: Turn the ignition switch OFF after the symptom is simulated the 1st time. Then repeat the simulation process again. When the problem has been simulated twice, the MIL lights up and the DTCs are recorded in the ECM. Check the 1st trip DTC using Mode 7 (Continuous Test Results) for SAE J1979.

1. Prepare the OBD II scan tool (complying with SAE J1978) or hand-held tester.
2. Connect the OBD II scan tool or hand-held tester to the DLC3 at the lower center of the instrument panel. see scheme 1 Turn the ignition switch ON and push the OBD II scan tool or hand-held tester switch ON.
3. Use the OBD II scan tool or hand-held tester to check the DTC and freeze frame data and note them down. For operating instructions, see the OBD II scan tool's instruction book. If there is no DTC in normal mode, check the 1st trip DTC using Continuous Test Results function (Mode 7 for SAE J1979) on OBD II scan tool or hand-held tester.
4. Confirm the details of the DTC and perform appropriate test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151954-S05451980122003010900000) table.
5. After repairs for DTC have been completed, DTC must be cleared from engine control module (ECM). See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151954-S22549028572003010900000). Road test vehicle to ensure all symptoms and/or complaints have been repaired.

CHECK Mode DTC Retrieval (Hand-Held Tester Only)

Note. If the hand-held tester switches the ECM from the normal mode to the check mode or vice-versa, or if the ignition switch is turned from ON to ACC or OFF during the check mode, the DTCs and freeze frame data will be erased.

Compared to the normal mode, the check mode has an increased sensitivity to detect malfunction. Furthermore, the same diagnostic items which are detected in the normal mode can also be detected in the check mode.

1. Ensure vehicle battery positive voltage is 11 V or more. Apply parking brake. Place transaxle in P or N. Ensure A/C and ignition are off. Check that throttle valve is fully closed.
2. Prepare the hand-held tester and connect it to the DLC3 at the lower center of the instrument panel. see scheme 1
3. Turn ignition ON and then turn hand-held tester ON.
4. Switch hand-held tester from the normal mode to the check mode. Check that the malfunction indicator light (MIL) on instrument cluster flashes to indicate CHECK mode operation.
5. Start the engine. If no DTCs are present, MIL will turn off. Simulate the conditions of the malfunction described by customer. NOTE: Leave the ignition switch ON until you have checked the DTC, etc. Turning the ignition switch OFF switches the diagnosis system from the check mode to the normal mode, so all DTCs, etc. are erased.
6. After simulating the malfunction conditions, use the hand-held tester diagnosis selector to check the DTC and freeze frame data, etc. If driveability problem exists and no DTCs are present, go to «TROUBLE SHOOTING - NO CODES»(ref-151977) article for diagnosis by symptom.
7. If any DTCs exist, perform appropriate DTC test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-151954-S06837564092003010900000).
8. After repairs for DTC have been completed, DTC must be cleared from engine control module (ECM). See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-151954-S22549028572003010900000). Road test vehicle to ensure all symptoms and/or complaints have been repaired.

CLEARING DIAGNOSTIC TROUBLE CODES

The DTCs and freeze frame data will be erased by either of the following actions

1. Operating the OBD II scan tool (complying with SAE J1978) or hand-held tester to erase the codes. See the OBD II scan tool's instruction book for operating instructions.
2. DTCs and freeze frame data may also be cleared by removing EFI No. 1 fuse (15-amp). The EFI No. 1 fuse is located in fuse/relay box at driver's side front corner of engine compartment. DTCs and freeze frame data may also be cleared by disconnecting negative battery cable. However, other various memory functions such as the clock, radio, alarm, seats, etc. will be cleared and must be reset.

BASIC INSPECTION

When the malfunction code is not confirmed in the DTC check, trouble shooting should be performed in order for all possible circuits to be considered as the cause of the problems. In many cases, by carrying out the basic engine check shown in the following flowchart, the location causing the problem can be found quickly and efficiently. Therefore, use of this check is essential in engine trouble shooting. (Scheme 59)- (Scheme 61).

Scheme 59

Scheme 60

Scheme 61

TEST DRIVE CONFIRMATION

1. On certain diagnostic trouble codes (DTC), once DTC has been cleared from engine control module (ECM) memory, test drive confirmation can be performed to verify repairs are made and that DTC does not reset. Test drive confirmation will duplicate conditions required to set specified DTCs.
2. Test drive confirmation lists the procedure to be performed to check that DTC does not reset. Test drive confirmation applies only to specific DTCs. Test drive confirmation will be included within proper DTC test under DIAGNOSTIC TESTS.

DATA LINK CONNECTOR NO. 3 INSPECTION

1. If your display shows UNABLE TO CONNECT TO VEHICLE when you have connected the cable of the OBD II scan tool or hand-held tester to the DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side. If communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle. Go to next step. If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.
2. Measure voltage between body ground and specified DLC3 terminals. See «INSPECTING DATA LINK CONNECTOR NO. 3 CONDITION»(ref-151954-S29299454642003010900000) table. (Scheme 62) The vehicle's ECM uses ISO 9141-2 for communication. The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

INSPECTING DATA LINK CONNECTOR NO. 3 CONDITION

Scheme 62

DIAGNOSTIC TROUBLE CODE DEFINITIONS

Note. If a malfunction code is displayed during the DTC check in check mode, check the circuit for the codes listed in the table below.

Note. Parameters listed below may not be exactly the same as your reading due to the type of instrument or other factors.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TESTS

Note. Before performing any diagnostic test, see SELF-DIAGNOSTIC SYSTEM for diagnostic system functions and system diagnostic procedures. Also check for any relate Technical Service Bulletins (TSBs).

Note. When performing diagnostic tests, it may be necessary to identify Engine Control Module (ECM) electrical connector terminals which are referenced to in testing procedure. (Scheme 63)

Scheme 63

Circuit Description

The variable valve timing (VVT) system controls the intake valve timing to proper timing in response to driving condition. The engine control module (ECM) controls the oil control valve (OCV) to make the intake valve timing properly, and, oil pressure controlled with OCV is supplied to the VVT controller, and then, VVT controller changes relative position between the camshaft and the crankshaft. Possible causes are

1. Open or short in OCV circuit.
2. Defective OCV.
3. Defective ECM.

Diagnosis & Repair

For diagnosis and repair (Scheme 64)- (Scheme 66).

Scheme 64

Scheme 65

Scheme 66

For wiring diagram, see DTC P0010: CAMSHAFT POSITION "A" ACTUATOR CIRCUIT (BANK NO. 1) & DTC P0020: CAMSHAFT POSITION "A" ACTUATOR CIRCUIT (BANK NO. 2). For diagnosis and repair (Scheme 67)- (Scheme 72).

Scheme 67

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Scheme 72

The camshaft position sensor (G (VV) signal) consists of a magnet, iron core and pickup coil. The G (VV) signal has 3 teeth on it's outer circumference and is installed to the camshaft timing gear. When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change, causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil. The actual camshaft angle is detected by the camshaft position sensor and it provides feedback to the engine control module (ECM) to control the intake valve timing in response to driving condition. Possible causes are

1. DTC P0016 Deviation in the crankshaft position sensor signal and VVT sensor (bank 1) signal (2 trip detection logic).
2. DTC P0018 Deviation in the crankshaft position sensor signal and VVT sensor (bank 2) signal (2 trip detection logic).
3. Mechanical system malfunction (jumping teeth of timing belt, belt stretched).
4. Defective ECM.

For diagnosis and repair (Scheme 73)

Scheme 73

For circuit description (Scheme 74)

Scheme 74

For diagnosis and repair (Scheme 75)and (Scheme 76).

Scheme 75

Scheme 76

For circuit description (Scheme 77)

Scheme 77

For diagnosis and repair (Scheme 78)- (Scheme 80).

Scheme 78

Scheme 79

Scheme 80

For circuit description (Scheme 77) For possible causes (Scheme 81)

Scheme 81

For diagnosis and repair (Scheme 82)

Scheme 82

For circuit description (Scheme 83)

Scheme 83

For diagnosis and repair (Scheme 84)- (Scheme 86).

Scheme 84

Scheme 85

Scheme 86

A thermistor built into the engine coolant temperature (ECT) sensor changes the resistance value according to the engine coolant temperature. The structure of the sensor and connector to the engine control module (ECM) is the same as in the intake air temperature circuit malfunction shown in DTC P0110: INTAKE AIR TEMPERATURE CIRCUIT . If the ECM detects DTC P0115, it operates the fail-safe function in which engine coolant temperature is assumed to be 176°F (80°C). Possible causes are

1. ECT sensor circuit is open and shorted.
2. Defective ECT sensor.
3. Defective ECM.

After confirming DTC P0115, use the OBD II scan tool or hand-held tester confirm the engine coolant temperature from the CURRENT DATA. See IDENTIFYING ENGINE COOLANT TEMPERATURE CURRENT DATA .

IDENTIFYING ENGINE COOLANT TEMPERATURE CURRENT DATA

For diagnosis and repair (Scheme 87)- (Scheme 89).

Scheme 87

Scheme 88

Scheme 89

For circuit description, see DTC P0115: ENGINE COOLANT TEMPERATURE CIRCUIT. For possible causes (Scheme 90)

Scheme 90

For diagnosis and repair (Scheme 91)

Scheme 91

For circuit description (Scheme 92)

Scheme 92

For diagnosis and repair (Scheme 93)and (Scheme 94).

Scheme 93

Scheme 94

For circuit description, see DTC P0120: THROTTLE/PEDAL POSITION SENSOR/SWITCH "A" CIRCUIT . Possible causes are

1. After vehicle speed has been exceeded 19 mph (30 km/h) even once, output value of the throttle position sensor is out of applicable range while vehicle speed is between 19 mph (30km/h) and 0 mph (0 km/h). (2 trip logic).
2. Defective throttle position sensor.

For diagnosis and repair (Scheme 95)

Scheme 95

If the water temperature becomes 167°F (75°C) or more, it is abnormal. If not due to the thermostat malfunction, it is abnormal. Possible causes are

1. If conditions are: after starting engine at 68°F (20°C), after engine is warmed up and THW is less than 167°F (75°C).
2. Defective thermostat.
3. Defective cooling system.
4. Defective engine coolant temperature (ECT) sensor.
5. Defective engine control module (ECM).

For diagnosis and repair (Scheme 96)

Scheme 96

For circuit description (Scheme 97)

Scheme 97

For wiring diagram (Scheme 75) For diagnosis and repair (Scheme 98)- (Scheme 103).

Scheme 98

Scheme 99

Scheme 100

Scheme 101

Scheme 102

Scheme 103

For circuit description, see DTC P0134: OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SENSOR 1) & DTC P0154: OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 2 SENSOR 1) . Possible causes are

1. When the heater operates, heater current exceeds 8 A (2 trip detection logic).
2. Heater current of 0.25 A or less when the heater operates (2 trip detection logic).
3. Open or short in heater circuit of A/F sensors (bank 1 and 2, sensor 1).
4. Defective A/F sensors (bank 1 and 2, sensor 1) heater.
5. Defective engine control module (ECM).

For wiring diagram, see DTC P0036: OXYGEN SENSOR HEATER CONTROL CIRCUIT (BANK NO. 1 SENSOR NO. 2). For diagnosis and repair (Scheme 104)

Scheme 104

Note. Bank 1 refers to the bank that includes cylinder No. 1. Sensor 2 refers to the sensor farther away from the engine body.

For circuit description, see DTC P0036: OXYGEN SENSOR HEATER CONTROL CIRCUIT (BANK 1 SENSOR 2) . Possible causes are

1. Voltage output of heated oxygen sensor remains at 0.4 V or more or 0.6 V or less when the vehicle is driven at 31 mph (50 km/h) or more after the engine is warmed up (2 trip detection logic).
2. Open or short in heated oxygen sensor circuit.
3. Defective heated oxygen sensor.

For wiring diagram, see DTC P0036: OXYGEN SENSOR HEATER CONTROL CIRCUIT (BANK NO. 1 SENSOR NO. 2). For diagnosis and repair (Scheme 105)

Scheme 105

For wiring diagram, see DTC P0036: OXYGEN SENSOR HEATER CONTROL CIRCUIT (BANK NO. 1 SENSOR NO. 2). For diagnosis and repair (Scheme 106)- (Scheme 111).

Scheme 106

Scheme 107

Scheme 108

Scheme 109

Scheme 110

Scheme 111

For diagnosis and repair (Scheme 112)- (Scheme 116).

Scheme 112

Scheme 113

Scheme 114

Scheme 115

Scheme 116

Each of the knock sensors is fitted to the right bank and left bank of the cylinder block to detect engine knocking. This sensor contains a piezoelectric element which generates a voltage when it becomes deformed, which occurs when the cylinder block vibrates due to knocking. If engine knocking occurs, ignition is retarded to suppress it. Possible causes are

1. No knock sensor No. 1 or No. 2 signal to ECM with engine speed between 2000 RPM and 5600 RPM.
2. Knock sensor No. 1 or No. 2 circuit is open or shorted.
3. Defective or loose knock sensor No. 1 or No. 2.
4. Defective engine control module (ECM).

If the ECM detects the above diagnosis conditions, it operates the fail-safe function in which the corrective retard angle value is set to the maximum value.

For diagnosis and repair (Scheme 117)- (Scheme 119).

Scheme 117

Scheme 118

Scheme 119

Crankshaft position sensor (NE signal) consists of a magnet, iron core and pickup coil. The NE signal plate has 34 teeth and is installed the crankshaft timing pulley. The NE signal sensor generates 34 signals at every engine revolution. The engine control module (ECM) detects the crankshaft angle and engine revolution by the NE signal. In addition to them, the ECM detects distinction of the cylinder and phase of the VVT by combining the G (VV) signal with the NE signal. Possible causes are

1. P0335 Only No crankshaft position sensor signal to ECM during cranking (2 trip detection logic).
2. P0335 Only No crankshaft position sensor signal to ECM with engine speed 600 RPM or more (2 trip detection logic).
3. P0339 Only No crankshaft position sensor signal to ECM with engine speed 1000 RPM or more.
4. Crankshaft position sensor circuit is open or shorted.
5. Defective crankshaft position sensor.
6. Defective timing pulley.
7. Defective ECM.

For wiring diagram, see DTC P0016: CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELATION (BANK NO. 1 SENSOR "A") & DTC P0018 CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELATION (BANK NO. 2 SENSOR "A"). For diagnosis and repair (Scheme 120)

Scheme 120

For wiring diagram, see DTC P0016: CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELATION (BANK NO. 1 SENSOR "A") & DTC P0018 CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELATION (BANK NO. 2 SENSOR "A"). For diagnosis and repair (Scheme 121)

Scheme 121

For diagnosis and repair (Scheme 122)- (Scheme 126).

Scheme 122

Scheme 123

Scheme 124

Scheme 125

Scheme 126

For circuit description (Scheme 127)

Scheme 127

For diagnosis and repair (Scheme 128)

Scheme 128

For circuit description (Scheme 129)and (Scheme 130).

Scheme 129

Scheme 130

Note. If DTC P0441 (purge flow), P0446 (VSV for CCV or VSV for pressure switching valve), P0450 or P0451 (evaporative pressure sensor) is output with DTC P0442 or P0456, first trouble shoot DTC P0441, P0446, P0450 or P0451. If no malfunction is detected, trouble shoot DTC P0442 or P0456 next. Read freeze frame data using OBD II scan tool or held-held tester. Freeze frame records the engine conditions when the malfunction is detected. When trouble shooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction. When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the vapor pressure sensor.

For diagnosis and repair with hand-held tester (Scheme 131)- (Scheme 150). For diagnosis and repair with OBD II scan tool (excluding hand-held tester) (Scheme 151)- (Scheme 158).

Scheme 131

Scheme 132

Scheme 133

Scheme 134

Scheme 135

Scheme 136

Scheme 137

Scheme 138

Scheme 139

Scheme 140

Scheme 141

Scheme 142

Scheme 143

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Scheme 145

Scheme 146

Scheme 147

Scheme 148

Scheme 149

Scheme 150

Scheme 151

Scheme 152

Scheme 153

Scheme 154

Scheme 155

Scheme 156

Scheme 157

Scheme 158

For circuit description (Scheme 159)and (Scheme 160).

Scheme 159

Scheme 160

Confirmation Readiness Test

For confirmation readiness test (Scheme 161)and (Scheme 162).

Scheme 161

Scheme 162

For wiring diagram, see DTC P0441: EVAP INCORRECT PURGE FLOW & DTC P0446: EVAP VENT CONTROL MALFUNCTION. For diagnosis and repair (Scheme 163)- (Scheme 171).

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

Scheme 168

Scheme 169

Scheme 170

Scheme 171

For circuit description (Scheme 172)

Scheme 172

For wiring diagram, see DTC P0441: EVAP INCORRECT PURGE FLOW & DTC P0446: EVAP VENT CONTROL MALFUNCTION. For diagnosis and repair (Scheme 173)

Scheme 173

For circuit description (Scheme 174)

Scheme 174

For diagnosis and repair (Scheme 175)and (Scheme 176).

Scheme 175

Scheme 176

For circuit description (Scheme 177)

Scheme 177

For diagnosis and repair (Scheme 178)- (Scheme 180).

Scheme 178

Scheme 179

Scheme 180

Note. If DTC P0560 appears, the engine control module (ECM) does not store another DTC.

Battery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is OFF for use by the DTC memory and air-fuel ratio adaptive control value memory, etc. Possible causes are

1. Open in back up power source circuit.
2. Defective ECM.

For diagnosis and repair (Scheme 181)

Scheme 181

Note. After confirming DTC P0705 and P0850, use the hand-held tester to confirm the park/neutral position (PNP) switch signal from the CURRENT DATA.

The PNP goes on when the shift lever is in the N or P shift position. When it goes on, terminal NSW of the engine control module (ECM) is grounded to body ground via the starter relay, thus the terminal NSW voltage becomes 0 V. When the shift lever is in the D, 2, L or R position, the PNP switch goes off, so the voltage of the ECM. Terminal NSW becomes battery voltage, the voltage of the ECM internal power source. If the shift lever is moved from the N position to the D position, this signal is used for air-fuel ratio correction and for idle speed control (estimated control), etc. Possible causes are

1. DTC P0705 Two or more switches are ON simultaneously for R, N, 2 and L positions (2 trip detection logic).
2. DTC P0850 When the vehicle speed is 25 mph (40 km/h) or more and the engine speed is between 1500-4000 RPM for 30 seconds or more with the park/neutral position switch ON (N position), 2 trip detection logic.
3. Short in PNP switch circuit.
4. Defective PNP switch.
5. Defective ECM.

Note. Read freeze frame data using OBD II scan tool or hand-held tester. Because freeze frame records the engine conditions when the malfunction is detected. When trouble shooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

For wiring diagram and diagnostic procedure, see appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.

This signal is used to detect when the brakes have been applied. The STP signal voltage is the same as the voltage supplied to the stop lights. The STP signal is used mainly to control the fuel cut off engine speed (the fuel cut off engine speed is reduced slightly when the vehicle is braking). Possible causes are

1. Stop light switch does not turn off when driving repeatedly at 19 mph (30 km/h) or more 10 times or more after depressing the brake (2 trip detection logic).
2. Short in stop light switch signal circuit.
3. Defective stop light switch.
4. Defective engine control module (ECM).

For diagnosis and repair (Scheme 182)and (Scheme 183).

Scheme 182

Scheme 183

For wiring diagram, see DTC P0036: OXYGEN SENSOR HEATER CONTROL CIRCUIT (BANK NO. 1 SENSOR NO. 2). For diagnosis and repair (Scheme 184)- (Scheme 189).

Scheme 184

Scheme 185

Scheme 186

Scheme 187

Scheme 188

Scheme 189

For circuit description, refer to DTC P0134. See DTC P0134: OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK NO. 1 SENSOR NO. 1) & DTC P0154: OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK NO. 2 SENSOR NO. 1) . Possible causes are

1. Defective air-fuel ratio (A/F) sensor.
2. Open or short in A/F sensor circuit (2 trip detection logic).
3. Defective engine control module (ECM).

For wiring diagram, see DTC P0036: OXYGEN SENSOR HEATER CONTROL CIRCUIT (BANK NO. 1 SENSOR NO. 2). For diagnosis and repair (Scheme 190)

Scheme 190

For circuit description, see DTC P0134: OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK NO. 1 SENSOR NO. 1) & DTC P0154: OXYGEN SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK NO. 2 SENSOR NO. 1) . Possible causes are

1. If the response characteristic of the air-fuel ratio (A/F) sensor becomes deteriorated (2 trip detection logic) after the engine is warmed up and the vehicle's engine speed is 1400 RPM or more and the vehicle speed 38 mph (60 km/h) or more.
2. Open or short in air-fuel ratio (A/F) sensors (bank No. 1, 2 sensor No. 1) circuit.
3. Defective A/F sensors (bank No. 1, 2 sensor No. 1)
4. Defective air induction system.
5. Defective fuel pressure.
6. Defective injector.
7. Defective engine control module (ECM).

For wiring diagram, see DTC P0036: OXYGEN SENSOR HEATER CONTROL CIRCUIT (BANK NO. 1 SENSOR NO. 2). For diagnosis and repair (Scheme 191)- (Scheme 196).

Scheme 191

Scheme 192

Scheme 193

Scheme 194

Scheme 195

Scheme 196