Engine Controls - Tests W/codes - Testing - 2.4: Diagnosis Nissan Altima L30

DTC Confirmation Test "A"

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and wait at least 6 seconds. Select MODE 7.
2. Using MIL, turn ignition on. Wait 6 seconds and turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

DTC Confirmation Test "B"

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and wait 5 seconds or less. Select MODE 7.
2. Using MIL, turn ignition on and wait 5 seconds or less. Turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

DTC Confirmation Test "C"

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and warm to operating temperature. Run engine for at least 10 seconds at idle speed and select MODE 7.
2. Using MIL, start engine and warm to operating temperature. Run engine for at least 10 seconds and turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

DTC Confirmation Test "D"

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and warm to operating temperature. Select MODE 1 and monitor mass airflow sensor. Increase engine speed to 4000 RPM. Mass airflow sensor output should rise with engine speed increased.
2. Using MIL, start engine and warm to operating temperature. Using DVOM, measure voltage between PCM terminal No. 47 and ground. see scheme 2 While monitoring DVOM, increase engine speed to 4000 RPM. Voltage should rise with engine speed increased.

DTC CONFIRMATION IDENTIFICATION (DTC P0100)

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and wait at least 6 seconds. Select MODE 7.
2. Using MIL, turn ignition on. Wait 6 seconds and turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and warm to operating temperature. Turn ignition off. Wait at least 5 seconds and restart engine. Run engine for at least 15 seconds at idle speed and select MODE 7.
2. Using MIL, start engine and warm to operating temperature. Turn ignition off. Wait at least 5 seconds and restart engine. Run engine for at least 15 seconds and turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on. Select MODE 1 then MAP on scan tool. Start engine and ensure AP sensor pressure is 6.7 psi (.47 kg/cm 2 ) or more.
2. Using MIL, start engine and warm to operating temperature. Using DVOM, measure voltage between PCM terminal No. 66 and ground by backprobing. see scheme 2 Voltage should be more than 1.74 volts.

DTC CONFIRMATION IDENTIFICATION (DTC P0105)

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and wait at least 5 seconds. Select MODE 7.
2. Using MIL, turn ignition on. Wait 5 seconds and turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and warm to operating temperature. Turn ignition off and allow engine to cool to 194° (90°C). Turn ignition on. Start engine and operate vehicle at 43 MPH for at least 100 seconds then select MODE 7.
2. Using MIL, start engine and warm to operating temperature. Stop engine and leave ignition on. Using DVOM, measure voltage between PCM connector terminal No. 51 and ground by backprobing. If voltage is more than 1.0 volt, turn ignition off and allow engine to cool down. Voltage will be less than 1.0 volt when engine is cooled down below 194°F (90°C). When engine is cooled down, start engine and operate vehicle at 43 MPH for at least 100 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

DTC Confirmation Test

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and wait at least 5 seconds. Select MODE 7.
2. Using MIL, turn ignition on. Wait 5 seconds and turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on. Start engine and drive vehicle for at least 5 seconds at 2 MPH then select MODE 7.
2. Using MIL, turn ignition on. Start engine and drive vehicle for at least 5 seconds at 2 MPH. Stop vehicle and turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and let idle for at least 15 seconds then select MODE 7.
2. Using MIL, start engine and let idle for at least 15 seconds then turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on. Using DVOM, backprobe and measure voltage between PCM harness connector terminals No. 47, 51 and ground. see scheme 2 Start engine and raise engine speed to 2000 RPM for at least 10 seconds. Voltage between PCM terminal No. 47 and ground should be at 3 volts or more and voltage between PCM terminal No. 51 and ground should be at 4 volts or more.
2. Using MIL, turn ignition on. Using DVOM, backprobe and measure voltage between PCM harness connector terminals No. 47, 51 and ground. see scheme 2 Start engine and raise engine speed to 2000 RPM for at least 10 seconds. Voltage between PCM terminal No. 47 and ground should be at 3 volts or more and voltage between PCM terminal No. 51 and ground should be at 4 volts or more. Turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

DTC CONFIRMATION IDENTIFICATION (DTC P0120)

Overall Function Test

Start engine and warm to operating temperature. Connect DVOM leads to PCM connector terminals No. 46 (positive lead) and No. 43 (negative lead) by backprobing connector. see scheme 2 While monitoring DVOM, increase engine speed to 2000 RPM under no load conditions.

1. To set DTC P0130, ensure voltage does not remain .2-.4 volt.
2. To set DTC P0133, ensure MIL turns on more than 5 times in 10 seconds.
3. To set DTC P0134, turn ignition on and wait 5 seconds. When using a scan tool, select MODE 3. When retrieving DTCs using MIL, turn ignition off and wait 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTICS in TESTS W/CODES - INTRODUCTION article.

Note. If diagnosing for DTC P0130 or P0134, start at step 3).

Start engine and warm to operating temperature. Connect DVOM leads to PCM harness connector terminals No. 46 (positive lead) and No. 43 (negative lead) by backprobing. see scheme 2 While monitoring DVOM, increase engine speed to 2000 RPM under no load conditions.

1. To set DTC P0131, ensure maximum voltage is more than .6 volt at least once and minimum voltage is below .35 volt at least once.
2. To set DTC P0132, ensure maximum voltage is less than .8 volt at least once and minimum voltage is below .35 volt at least once.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and let idle for at least 5 seconds then select MODE 3.
2. Using MIL, start engine and let idle for at least 5 seconds then turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS SYSTEM in TESTS W/CODES - INTRODUCTION article.

Start engine and warm to operating temperature. Connect DVOM leads to PCM connector terminals No. 52 (positive lead) and No. 43 (negative lead) by backprobing. While monitoring DVOM, increase engine speed to 4000 RPM under no load conditions and release accelerator pedal and repeat 10 times.

1. DTC P0137 will set if voltage is not less than .54 volt at least once.
2. DTC P0138 will set if voltage is not more than .56 volt at least once.
3. DTC P0139 will set if voltage does not change at least .06 volt for 1 second.
4. DTC P0140 will set if voltage is not less than 2 volts.

If DTC is not set, check voltage after allowing engine to idle for 10 minutes or check voltage while coasting at 50 mph with vehicle in 3rd gear and recheck voltage as described above.

Note. If diagnosing for DTC P0139 or P0140, start at step 3).

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and let idle for at least 5 seconds. Turn ignition off and wait 5 seconds. Start engine and let idle for at least 5 seconds then select MODE 3.
2. Using MIL, start engine and let idle for at least 5 seconds then turn ignition off. Wait at least 5 seconds and turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTICS SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and warm to operating temperature. Turn ignition off and wait 5 seconds. Disconnect MAF sensor harness connector. Start engine and let idle for at least 3 seconds. Turn ignition off and reconnect MAF sensor harness connector. Turn ignition on. Select MODE 7 and ensure that DTC P0100 is set. Select MODE 4 and erase DTCs. Start engine and let it idle for 10 minutes. Select MODE 7 and check for DTCs. If engine was difficult to start, attempt to start engine with accelerator pedal depressed fully. If engine starts, perform DTC procedure. If engine does not start, check for intake or exhaust leaks.
2. Using MIL, start engine and warm to operating temperature. Turn ignition off and wait 5 seconds. Disconnect MAF sensor harness connector. Start engine and let idle for at least 3 seconds. Turn ignition off and reconnect MAF sensor harness connector. Turn ignition on. Recheck codes and ensure DTC P0100 is set. Erase codes by switching PCM to MODE 1. If engine was difficult to start, attempt to start engine with accelerator pedal fully depressed. If engine starts, perform DTC procedure. If engine does not start, check for intake or exhaust leaks.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on. Wait 10 seconds then select MODE 7. If DTC is not set, select MODE 1 and monitor ECT sensor value. If engine temperature is more than 194°F (90°C), allow engine to cool. Turn ignition off then on again. Wait 10 seconds then select MODE 7.
2. Using MIL, turn ignition on. Wait 10 seconds then turn ignition off. Wait 5 seconds then turn ignition on. Recheck DTCs. If DTC is not set, connect DVOM between PCM connector terminal No. 51 and ground by backprobing connector. see scheme 2 If voltage is more than 1.0 volt, allow engine to cool down. When voltage is less than 1.0, turn ignition off. Turn ignition on and wait 10 seconds. Turn ignition off and 5 seconds. Turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and warm to operating temperature. Turn ignition off and wait 5 seconds. Start engine and drive vehicle at 1500-3000 RPM for at least 3 minutes. Hold accelerator pedal as steady as possible. Refer to freeze frame data for driving conditions in which DTC was set. Select MODE 7.
2. Using MIL, start engine and warm to operating temperature. Turn ignition off and wait 5 seconds. Start engine and drive vehicle at 1500-3000 RPM for at least 3 minutes. Hold accelerator pedal as steady as possible. Turn ignition off and wait 5 seconds. Turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and idle for at least 5 seconds. Select MODE 3.
2. Using MIL, start engine and idle for at least 5 seconds. Turn ignition off and wait 5 seconds. Turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and idle for at least 15 seconds (DTC P0335) or 2 minutes (DTC P1336). Select MODE 7.
2. Using MIL, start engine and idle for at least 15 seconds (DTC P0335) or 2 minutes (DTC P1336). Turn ignition off and wait 5 seconds. Turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, crank engine for at least 2 seconds. Select MODE 7.
2. Using MIL, crank engine for at least 2 seconds. Turn ignition off and wait 5 seconds. Turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

DTC Confirmation Tests "B" And "C"

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and idle for at least 2 seconds. Select MODE 3.
2. Using MIL, start engine and idle for at least 2 seconds. Turn ignition off and wait 5 seconds. Turn ignition on. Retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Raise drive wheels and support vehicle. Start engine and warm to operating temperature. With transmission in "1" position, increase engine speed from 2000 RPM to 4000 RPM. Ensure EGR valve lifts up without sticking. Disconnect EGRC solenoid valve sub-harness connector. Retest EGR valve. If EGR valve does not operate normally, go to procedure. If EGR valve operates normally, diagnose EGR temperature sensor or circuit failure. See DTC P1401: EGR TEMPERATURE SENSOR .

Disconnect vacuum line to fuel pressure regulator and EGR valve. Disconnect vacuum line to EGRC-BPT valve from EGRC solenoid valve. Connect vacuum line from fuel pressure regulator to EGRC-BPT valve. Start engine and monitor EGR valve. EGR valve should remain closed or lift slightly during engine idle speed. With engine at 1500-3000 RPM, ensure EGR valve lifts and falls without sticking. If operation is not as specified, go to procedure. If operation is as specified, check vacuum line between EGRC solenoid valve and EGRC-BPT valve.

Start engine and warm to operating temperature. Turn ignition off. Using 2 DVOMs, connect leads by backprobing the connector in the following manner: see scheme 2

1. DVOM No. 1 positive lead connected to PCM connector terminal No. 46.
2. DVOM No. 1 negative lead connected to PCM harness connector terminal No. 43.
3. DVOM No. 2 positive lead connected to PCM harness connector terminal No. 52.
4. DVOM No. 2 negative lead connected to PCM harness connector terminal No. 106.

DVOM No. 1 is measuring front HO2S voltage and DVOM No. 2 is measuring rear HO2S voltage. Start engine and increase to 2000 RPM and hold steady. Monitor DVOMs and ensure DVOM No. 2 voltage switching frequency (between high and low voltage) is at least 25 percent slower than DVOM No. 1. If operation is not as specified, three way catalyst is not operating properly. If voltage of DVOM No. 1 does not switch (between high and low voltage) at least 5 times within 10 seconds, diagnose fault in front HO2S circuit. See DTC P0130, P0133 OR P0134: FRONT HEATED OXYGEN SENSOR (HO2S) .

Depending on equipment available, use one of the following to set DTC

Using generic scan tool

1. Drive vehicle according to specified driving pattern to set System Readiness Test (SRT) codes. See SYSTEM READINESS TEST (SRT) CODES under ADDITIONAL SYSTEM FEATURES in TESTS W/CODES - INTRODUCTION article. Stop vehicle and go to next step.
2. Select MODE 1 on scan tool and check SRT status of EVAP system. If EVAP system SRT is complete, system is okay at this time. Retest system and diagnose by symptom is fault exists with no code. See TESTS W/O CODES article. If EVAP system SRT is incomplete, turn ignition off, wait 5 seconds and go to next step.
3. Perform driving pattern again. Select MODE 3 on scan tool. If DTC P0440, P1440 or P1447 is set, perform appropriate diagnostic procedure. If DTC P0440, P1440 or P1447 is not set, go back to step 2).

Using MIL

1. Using MIL, drive vehicle according to specified driving pattern to set System Readiness Test (SRT) codes. See SYSTEM READINESS TEST (SRT) CODES under ADDITIONAL SYSTEM FEATURES in TESTS W/CODES - INTRODUCTION article. Turn ignition off and wait 5 seconds. Perform driving pattern again. Stop vehicle and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and idle for at least 13 seconds. Select MODE 7 on scan tool.
2. Using MIL, start engine and idle for at least 13 seconds. Turn ignition off and wait 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and idle for at least 5 seconds. Select MODE 7 on scan tool.
2. Using MIL, start engine and idle for at least wait 5 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and warm to operating temperature. Turn ignition off and wait at least 5 seconds. Turn ignition on. Using DVOM, measure voltage between PCM harness connector terminal No. 63 and ground by backprobing. see scheme 2 Ensure voltage is less than 4.2 volts. Start engine and idle for at least 20 seconds. Select MODE 7 on scan tool.
2. Using MIL, start engine and warm to operating temperature. Turn ignition off and wait at least 5 seconds. Turn ignition on. Using DVOM, measure voltage between PCM harness connector terminal No. 63 and ground by backprobing. see scheme 2 Ensure voltage is less than 4.2 volts. Start engine and idle for at least 20 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to check overall circuit function

1. Using generic scan tool, raise drive wheels off ground and support vehicle. Start engine. With transmission in "D" position and wheels turning at 6 mph, select MODE 1 and check VSS output signal.
2. Using MIL, raise drive wheels off ground and support vehicle. Connect an oscilloscope between PCM harness connector terminal No. 26 and ground by backprobing. see scheme 2 Start engine. With transmission in "D" position and wheels turning at 6 mph, ensure VSS output signal is a 4.2 volt (average) square waveform.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and wait at least 2 seconds. Select MODE 7 on scan tool.
2. Using MIL, turn ignition on and wait 2 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and warm to operating temperature. Turn ignition off and wait at least 5 seconds. Start engine and idle for at least one minute. Select MODE 7 on scan tool.
2. Using MIL, start engine and warm to operating temperature. Turn ignition off and wait 5 seconds. Start engine and idle for at least one minute. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Start engine and warm to operating temperature. Using DVOM, measure voltage between PCM harness connector terminal No. 27 and ground by backprobing. see scheme 2 Battery voltage should exist at idle. Approximately zero volts should exist with engine at 2000 RPM.

Start engine. Using DVOM, measure voltage between PCM connector terminal No. 24 and ground by backprobing connector. see scheme 2 Also measure voltage between PCM connector terminal No. 29 and ground. Voltage should be approximately 7 volts.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and idle for at least 30 seconds. Select MODE 7 on scan tool.
2. Using MIL, start engine and idle for at least 30 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and wait at least 10 seconds. Select MODE 7 on scan tool.
2. Using MIL, turn ignition on and wait 10 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Start engine and warm to operating temperature. Using DVOM, measure voltage between PCM connector terminal No. 46 (positive lead) and terminal No. 43 (negative lead) by backprobing connector. see scheme 2 Monitor DVOM with engine at 2000 RPM. Voltage should be less than.23 volt at least once and more than.61 volt at least once.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on. Start engine. If engine will not start, turn ignition to START position for at least 5 seconds. Select MODE 7 on scan tool.
2. Using MIL, turn ignition on. Start engine. If engine will not start, turn ignition to START position for at least 5 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Diagnostic Aid

If engine will start and idle, start at step 4). If engine will not start, start at step 1.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and wait at least 5 seconds. Select MODE 7 on scan tool.
2. Using MIL, turn ignition on and wait 5 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and select MODE 1 on scan tool. Ensure engine coolant temperature is less than 104°F (40°C). If engine temperature is more than specified, allow engine to cool down. Start engine and idle for at least 8 seconds. Select MODE 7 on scan tool.
2. Using MIL, turn ignition on. Using DVOM, measure voltage between PCM harness connector terminal No. 51 and ground by backprobing. see scheme 2 If voltage is 1.5 volts or less, allow engine to cool. Start engine and idle for at least 8 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool or MIL, start engine and warm to operating temperature. Once engine is warmed up, idle engine for an additional 2 minutes. With engine idling, ensure EGR valve is not lifting. If EGR valve lifts at idle, diagnose fault in EGR valve function. See «DTC P0400: EGR FUNCTION»(ref-18071-S33339687532000122900000) or «DTC P0402: EGR CONTROL BACKPRESSURE TRANSDUCER (EGRC-BPT)»(ref-18071-S22873190802000122900000) VALVE. If EGR is not lifting, measure voltage between PCM harness connector terminal No. 62 and ground by backprobing. see scheme 2 While monitoring DVOM, increase engine speed to 1500 and open EGR valve manually. If voltage drops to less than one volt, diagnose fault in EGR valve function.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, turn ignition on and select MODE 1 on scan tool. Ensure engine coolant temperature is 14-104°F (-10-40°C). Using DVOM, measure voltage between PCM harness connector terminal No. 62 and ground by backprobing. see scheme 2 Ensure voltage is less than 4.8 volts. Start engine and idle for at least 60 seconds. Turn engine off. Select MODE 3 on scan tool.
2. Using MIL, turn ignition on. Using DVOM, measure voltage between PCM harness connector terminal No. 51 and ground by backprobing. see scheme 2 If voltage is 1.5 volts or less, allow engine to cool. Measure voltage between PCM connector terminal No. 62 and ground by backprobing connector. Ensure voltage is 4.8 volts or less. Start engine and idle for at least 60 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Raise drive wheels and support vehicle. Start engine and warm to operating temperature. Turn ignition off and wait 5 seconds. Start engine and idle for at least 70 seconds. Using DVOM, measure and record voltage between PCM harness connector terminals No. 67 (positive lead) and terminal No. 43 (negative lead) by backprobing. see scheme 2 While monitoring voltage, maintain the following conditions for at least 1 minute

1. A/C On
2. Steering Wheel Turned Fully
3. Headlights On
4. Rear Window Defogger On
5. Engine Speed At 3000 RPM
6. Transmission In Any Forward Gear

Ensure voltage remains at least .1 volt less than voltage measured at idle.

Note. If both DTC P0510 and P1447 are retrieved, diagnose and repair DTC P0510 before proceeding with DTC P1447 repair procedures.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and idle at least 5 seconds. Select MODE 7 on scan tool.
2. Using MIL, start engine and idle at least 5 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Remove vacuum cut valve and vacuum cut valve bypass valve. see scheme 22 Check vacuum cut valve operation. Go to step 2) of procedure.

Depending on equipment available, use one of the following to set DTC

1. Using generic scan tool, start engine and idle for at least 40 seconds. Select MODE 7 on scan tool.
2. Using MIL, start engine and idle for at least 40 seconds. Turn ignition off and wait at least 5 seconds. Turn ignition on and retrieve DTCs using MIL. See SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Turn ignition on. Using DVOM, measure voltage between PCM harness connector terminal No. 22 and ground by backprobing. see scheme 2 With either A/T in "P" or "N" position or M/T in "N" position, voltage should be zero volts. With transmission in any other position, voltage should be 5 volts.

Note. Steps 1-3 are for M/T models. For A/T models, go to step 4.

Scheme 5

Scheme 6

1. Turn ignition off. Disconnect neutral position switch harness connector. (Scheme 5) Using DVOM, check continuity between harness connector terminal No. 4 (Black wire) and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between switch and ground.
2. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between neutral position switch harness connector terminal No. 2 (Green/Orange wire) and PCM harness connector terminal No. 22. see scheme 2and see scheme 32. If continuity exists, go to next step. If continuity does not exist, repair open in Green/Orange wire between PCM and neutral position switch.
3. Using DVOM, check continuity as follows: see scheme 32 With gear selector in Neutral, continuity should exist between neutral position switch terminals No. 2 and 4. With gear selector in any other position, continuity should not exist between any terminals. If continuity is not as specified, replace neutral position switch. If continuity is as specified, check PCM pins and terminals for damage and check connection of PCM harness connector. Reconnect PCM harness connector and retest system. NOTE: Steps 4-7 are for A/T models. For M/T models, go to step 1.
4. Disconnect inhibitor switch harness connector. Turn ignition on. Using DVOM, measure voltage between inhibitor switch harness connector terminal No. 3 (Yellow wire) and ground. (Scheme 6) If battery voltage is present, go to next step. If battery voltage is not present, check for blown fuse, or open or short in Yellow wire circuit. See WIRING DIAGRAMS article.
5. Turn ignition off. Disconnect TCM harness connector. see scheme 26 Using DVOM, check continuity between TCM harness connector terminal No. 19 and inhibitor switch harness connector terminal No. 6 (Gray/Red wire) and terminal No. 9 (Gray/Red wire). see scheme 27 If continuity exists, go to next step. If continuity does not exist, repair open in Gray/Red wire as required.
6. Disconnect PCM harness connector. see scheme 1 Using DVOM, check continuity between PCM harness connector terminal No. 22 and TCM harness connector terminal No. 13 (Green/Orange wire). see scheme 2and see scheme 27. If continuity exists, go to next step. If continuity does not exist, repair open or short in Green/Orange wire between PCM and TCM.
7. Turn ignition on. Using DVOM, measure battery voltage between TCM harness connector and ground as follows: see scheme 27 With gear selector in Park or Neutral, battery voltage should be present at TCM harness connector terminal No. 19. With gear selector in Reverse, battery voltage should be present at TCM harness connector terminal No. 20. With gear selector in Drive, battery voltage should be present at TCM harness connector terminal No. 18. With gear selector in "2", battery voltage should be present at TCM harness connector terminal No. 17. With gear selector in "1", battery voltage should be present at TCM harness connector terminal No. 16. In all other gear positions, voltage should be zero. If voltage is not as specified, replace inhibitor switch. If voltage is as specified, check PCM pins and terminals for damage and check connection of PCM harness connector. Reconnect PCM harness connector and retest system.

Ensure that engine does not overheat during any part of overall function test.

Start engine. Set climate controls to full cold position. Turn A/C and blower fan on. Allow engine to idle with A/C on. Ensure cooling fan operates at low speed. Turn ignition off. Turn A/C and blower fan off. Disconnect ECT sensor harness connector. Connect a 150 ohm resistor between ECT harness connector terminals. Start engine and ensure cooling fan operates at higher than low speed.