This is huge, but it's for those of you that don't have the service manual so here you go:
HJ40 DTC P0402: OUTPUT ALL DIAGNOSTIC TROUBLE CODES (DTC)
Diagnostic Trouble Code (DTC) P0402 indicates that self-test has detected EGR flow.
Possible causes:
Non-seated EGR valve.
Damaged EGR valve.
Damaged EGR Valve Position (EGR V.P.) sensor.
Plugged or pinched EGR valve vacuum hose.
Plugged or iced EGR Vacuum Regulator (EGR V.R.) solenoid vent.
EVR circuit shorted to GND.
Damaged EGR Vacuum Regulator solenoid.
Damaged PCM.
Output all Diagnostic Trouble Codes (DTCs).
Is DTC P1409 present?
Yes No
GO to HJ20 . GO to HJ41 .
HJ41 CHECK EGRVP PID VOLTAGE WITH ENGINE OFF
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Note: The EGR Valve Position sensor voltage with the EGR valve closed is between 0.24 and 0.67 volt.
Does the EGRVP PID indicate a voltage greater than 0.67 volt?
Yes No
The EGRVP PID is indicating a voltage greater than the acceptable closed EGR valve voltage. GO to HJ42 . GO to HJ44 .
HJ42 CHECK EGRVP PID VOLTAGE WITH EGR VACUUM HOSE DISCONNECTED
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Disconnect vacuum hose at EGR valve to allow trapped vacuum to vent if any.
Does the EGRVP PID voltage drop to an acceptable level between 0.24 and 0.67 volts?
Yes No
INSPECT EGR Vacuum Regulator solenoid hoses for a pinched, plugged or damaged hose. If OK, REPLACE EGR Vacuum Regulator solenoid. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . GO to HJ43 .
HJ43 EXERCISE EGR VALVE WITH ENGINE RUNNING
Key off.
EGR valve vacuum hose disconnected.
Connect a hand vacuum pump at the EGR valve.
Start engine.
Access EGRVP PID with a Scan Tool.
Exercise EGR valve by applying 5-10 in-Hg (17-34 kPa) vacuum to the EGR valve and releasing it. Repeat this several times, and in between each time, tap on EGR valve lightly with a small solid object (screwdriver handle) in an attempt to dislodge contamination from valve if any.
Does the EGRVP PID voltage drop to an acceptable level between 0.24 and 0.67 after several attempts at dislodging foreign material?
Yes No
DTC P0402 was the result of EGR valve binding or foreign contamination. SERVICE as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test. REMOVE EGR valve and EGR Valve Position sensor and INSPECT closely for damage. If none is evident, REPLACE EGR valve. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . If DTC is still present, REPLACE EGR Valve Position sensor.
HJ44 CHECK EGRVP PID VOLTAGE WITH ENGINE RUNNING
Key on, engine running.
Access EGRVP PID with a Scan Tool.
Note: The EGR Valve Position sensor voltage with the EGR valve closed is between 0.24 and 0.67 volts.
Does the EGRVP PID indicate a voltage greater than 0.67 volts with the engine running at idle?
Yes No
This indicates that the fault is in the vacuum control side of the EGR system. GO to HJ45 . The fault that produced DTC P0402 is intermittent. GO to HJ46 .
HJ45 CHECK EGR VACUUM REGULATOR SOLENOID
Key off.
Remove the EGR Vacuum Regulator solenoid vent cap and inspect the vent for plugging.
Verify that the EGR Vacuum Regulator solenoid hoses are installed and routed properly.
Are the solenoid vacuum hoses and vent OK?
Yes No
REPLACE the EGR Vacuum Regulator solenoid. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . SERVICE as necessary. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ46 CHECK EGR SYSTEM FOR INTERMITTENT FAULT
Key off.
Disconnect EGR valve vacuum hose.
Connect a hand vacuum pump at the EGR valve.
Start engine.
Access EGRVP PID with a Scan Tool.
Exercise EGR valve by applying 5-10 in-Hg (17-34 kPa) vacuum to the EGR valve and releasing it. Repeat this several times. On a normal functioning system, the EGRVP PID voltage will be between 0.24 and 0.67 volt each time the vacuum is released. As an indication of a fault, look for the voltage to hang up above 0.67 volt after vacuum is released.
Does the EGRVP PID voltage drop to an acceptable level, between 0.24 and 0.67 volt each time the vacuum is released?
Yes No
RECONNECT EGR valve vacuum hose. GO to HJ47 . ISOLATE fault and SERVICE as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ47 CHECK FOR INTERMITTENT EGR VALVE POSITION SENSOR AND EGR VACUUM REGULATOR SOLENOID
Key on, engine running.
Access EGRVP PID with a Scan Tool. The PID voltage should read between 0.24 and 0.67 volt with engine at idle.
Observe the EGRVP PID voltage to go greater than 0.67 volt as an indication of a fault while performing the following:
Lightly tap on the EGR V.P. sensor and connector.
Grasp the EGR V.R. sensor vehicle harness and wiggle wires between the sensor and PCM.
Lightly tap on the EGR V.P. solenoid vehicle harness connector.
Grasp the EGR V.R. solenoid vehicle harness and wiggle wires between the solenoid and PCM.
Is a fault indicated?
Yes No
ISOLATE fault and SERVICE as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . Unable to duplicate and/or identify fault at this time. GO to Pinpoint Test Step Z1 with the following data: EGRVP and EGRVR PIDs and list of possible causes.
HJ1 DTC P1400: ACCESS EGRVP PID WITH SCAN TOOL AND CHECK VOLTAGE
Diagnostic Trouble Code (DTC) P1400 indicates that self-test has detected a low voltage on EVP circuit.
Possible causes:
Open EVP circuit
Open VREF circuit
EVP circuit shorted to GND or SIG RTN
Damaged EGR Valve Position (EGR V.P.) sensor
Damaged PCM
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Note: EGR V.P. sensor voltage with the EGR valve closed is between 0.24 and 0.67 volts.
Is EGRVP PID voltage less than 0.2 volt?
Yes No
The EVP circuit voltage is less than the acceptable minimum. GO to HJ2 . The fault that produced DTC P1400 is intermittent. GO to HJ6 .
HJ2 INDUCE OPPOSITE EVP CIRCUIT VOLTAGE
Key off.
Disconnect EGR V.P. sensor vehicle harness connector.
Connect a jumper wire between the sensor VREF circuit and EVP circuit at the EGR V.P. sensor vehicle harness connector.
Key on, engine off.
Note: If a Scan Tool communication problem exists, remove jumper immediately and go directly to HJ3 .
Access EGRVP PID with a Scan Tool.
Is EGRVP PID voltage between 4.0 and 6.0 volts?
Yes No
REPLACE damaged EGR V.P. sensor. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . REMOVE jumper. GO to HJ3 .
HJ3 MEASURE VREF VOLTAGE AT EGR V.P. SENSOR
EGR V.P. sensor disconnected.
Key on, engine off.
Measure voltage between the sensor VREF circuit and SIG RTN circuit at the EGR V.P. sensor vehicle harness connector.
Is VREF voltage between 4.0 and 6.0 volts?
Yes No
GO to HJ4 . VREF voltage is out of range. GO to Pinpoint Test Step C1 .
HJ4 CHECK EVP CIRCUIT CONTINUITY
Key off.
EGR V.P. sensor disconnected.
Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Measure resistance between Test Pin 63 (EVP) and EVP circuit at the EGR V.P. sensor vehicle harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to HJ5 . SERVICE open in EVP circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test .
HJ5 CHECK EVP CIRCUIT FOR SHORTS TO PWR GND AND SIG RTN
Key off.
EGR V.P. sensor disconnected.
Breakout box installed, PCM disconnected.
Disconnect Scan Tool from DLC.
Measure resistance between Test Pin 63 (EVP) and Test Pins 91 (SIG RTN), 51 and 103 (PWR GND) at the breakout box.
Is each resistance greater than 10,000 ohms?
Yes No
REPLACE damaged PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test . SERVICE short circuit between EVP circuit and PWR GND or SIG RTN. REMOVE breakout box. RECONNECT all components. RERUN Quick Test .
HJ6 WIGGLE SENSOR AND HARNESS
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Observe EGRVP PID for an indication of a fault while performing the following:
Lightly tap on EGR V.P. sensor. Wiggle the sensor connector and vehicle harness between the sensor and PCM. A fault is indicated by a sudden change in EGRVP PID voltage.
Is a fault indicated?
Yes No
ISOLATE fault and SERVICE as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . Unable to duplicate and/or identify fault at this time. GO to Pinpoint Test Step Z1 with the following data: EGRVP and EGRVR PIDs and list of possible causes.
HJ10 DTC P1401: ACCESS EGRVP PID WITH SCAN TOOL AND CHECK VOLTAGE
Diagnostic Trouble Code (DTC) P1401 indicates that self-test has detected a high voltage on EVP circuit.
Possible causes:
EVP circuit shorted to PWR or VREF.
SIG RTN open.
Damaged EGR Valve Position (EGR V.P.) sensor.
Damaged PCM.
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Note: EGR V.P. sensor voltage with the EGR valve closed is between 0.24 and 0.67 volts.
Is EGRVP PID voltage greater than 4.0 volts?
Yes No
The EVP circuit voltage is greater than the acceptable maximum. GO to HJ11 . The fault that produced DTC P1401 is intermittent. GO to HJ15 .
HJ11 CHECK EVP CIRCUIT FOR SHORT TO PWR
Key off.
Disconnect EGR V.P. sensor vehicle harness connector.
Key on, engine off.
Measure voltage between EVP circuit at the EGR V.P. sensor vehicle harness connector and chassis ground.
Is voltage greater than 10.5 volts?
Yes No
The EVP circuit is indicating a short to PWR. GO to HJ12 . GO to HJ13 .
HJ12 CHECK EVP CIRCUIT FOR SHORT TO PWR IN HARNESS
Key off.
EGR V.P. sensor disconnected.
Disconnected PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Install breakout box, leave PCM disconnected.
Key on, engine off.
Measure voltage between Test Pin 63 (EVP) and Test Pins 51 and 103 (PWR GND) at the breakout box.
Is voltage greater than 10.5 volts?
Yes No
SERVICE short between EVP circuit and PWR circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test . REPLACE damaged PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test .
HJ13 MEASURE VREF VOLTAGE AT EGR V.P. SENSOR
EGR V.P. sensor disconnected.
Key on, engine off.
Measure voltage between the sensor VREF circuit and SIG RTN circuit at the EGR V.P. sensor vehicle harness connector.
Is VREF voltage between 4.0 and 6.0 volts?
Yes No
GO to HJ14 . VREF is out of range. GO to Pinpoint Test Step C1 .
HJ14 INDUCE OPPOSITE EVP CIRCUIT VOLTAGE
EGR V.P. sensor disconnected.
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Is EGRVP PID voltage less than 0.05 volt?
Yes No
REPLACE damaged EGR V.P. sensor. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . REPLACE damaged PCM. RECONNECT all components. RERUN Quick Test .
HJ15 WIGGLE SENSOR AND HARNESS
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Observe EGRVP PID for an indication of a fault while performing the following:
Lightly tap on EGR V.P. sensor. Wiggle the sensor connector and vehicle harness between the sensor and PCM. A fault is indicated by a sudden change in EGRVP PID voltage.
Is a fault indicated?
Yes No
ISOLATE fault and SERVICE as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . Unable to duplicate and/or identify fault at this time. GO to Pinpoint Test Step Z1 with the following data: EGRVP and EGRVR PIDs and list of possible causes.
HJ20 DTC P1409: MEASURE RESISTANCE ACROSS EGR VACUUM REGULATOR SOLENOID
Diagnostic Trouble Code (DTC) P1409 indicates that self-test has detected an electrical malfunction in the EGR Vacuum Regulator solenoid.
Possible causes:
Open EVR circuit.
EVR circuit shorted to PWR.
EVR circuit shorted to GND.
Open VPWR circuit to EGR Vacuum Regulator (EGR V.R.) solenoid.
Damaged EGR V.R. solenoid.
Damaged PCM.
Key off.
Disconnect EGR V.R. solenoid.
Measure EGR V.R. solenoid resistance.
Is solenoid resistance between 26 and 40 ohms?
Yes No
GO to HJ21 . REPLACE damaged EGR V.R. solenoid. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ21 MEASURE VPWR VOLTAGE AT EGR V.R. SOLENOID
EGR V.R. solenoid disconnected.
Key on, engine off.
Measure voltage between VPWR circuit at the EVR solenoid vehicle harness connector and CHASSIS GND.
Is voltage greater than 10.5 volts?
Yes No
GO to HJ22 . SERVICE open in VPWR circuit to EGR V.R. solenoid. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ22 CHECK EVR CIRCUIT CONTINUITY
Key off.
EGR V.R. solenoid disconnected.
Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Install breakout box, leave PCM disconnected.
Measure resistance between Test Pin 47 (EVR) and EVR circuit at the EGR V.R. solenoid vehicle harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to HJ23 . SERVICE open in EVR circuit. RECONNECT all components. RERUN Quick Test .
HJ23 CHECK EVR CIRCUIT FOR SHORTS TO PWR OR VREF
Key off.
EGR V.R. solenoid disconnected.
Breakout box installed, PCM disconnected.
Key on, engine off.
Measure voltage between Test Pin 47 (EVR) and Test Pins 51 or 103 (PWR GND) at the breakout box.
Is voltage greater than 1.0 volt?
Yes No
SERVICE EVR circuit for short to PWR or VREF. RECONNECT all components. RERUN Quick Test . GO to HJ24 .
HJ24 CHECK EVR CIRCUIT FOR SHORTS TO GND
Key off.
EGR V.R. solenoid disconnected.
Breakout box installed, PCM disconnected.
Measure resistance between Test Pin 47 (EVR) and Test Pins 51 and 103 (PWR GND) at the breakout box.
Is resistance greater than 10,000 ohms?
Yes No
GO to HJ25 . SERVICE EVR circuit for short to PWR GND. RECONNECT all components. RERUN Quick Test .
HJ25 WIGGLE EGR V.R. SOLENOID AND HARNESS WHILE MONITORING VOLTAGE AT PCM
Key off.
Breakout box installed, PCM disconnected.
Reconnect EGR V.R. solenoid.
Key on, engine off.
Measure voltage between Test Pin 47 (EVR) and Test Pins 51 or 103 (PWR GND) at the breakout box.
Voltage should read greater than 10.5 volts.
For an indication of a fault, look for this voltage to drop while performing the following:
Lightly tap on the solenoid.
Wiggle the solenoid connector.
Grasp the solenoid vehicle harness and wiggle wires between solenoid and PCM.
Is a fault indicated?
Yes No
ISOLATE fault and SERVICE as necessary. RECONNECT all components. RERUN Quick Test . If DTC P1409 can be duplicated, REPLACE damaged PCM. RECONNECT all components. RERUN Quick Test . Otherwise, unable to duplicate and/or identify fault at this time. GO to Pinpoint Test Step Z1 with the following data: EGRVP and EGRVR PIDs and list of possible causes.
HJ30 DTC P0401: CHECK VACUUM SUPPLY TO EGR VACUUM REGULATOR SOLENOID
Diagnostic Trouble Code (DTC) P0401 indicates that self-test has detected insufficient EGR flow.
Possible causes:
Disconnected or damaged vacuum hoses.
Damaged EGR valve.
Damaged EGR Valve Position (EGR V.P.) sensor.
Damaged EGR Vacuum Regulator (EGR V.R.) solenoid.
Key off.
Disconnect vacuum supply hose to EGR V.R. solenoid at the solenoid.
Connect the vacuum supply hose to a vacuum gauge.
Start engine and check the vacuum at idle.
Is the supply vacuum greater than 10 in-Hg (34 kPa)?
Yes No
REMOVE vacuum gauge and RECONNECT hose. GO to HJ31 . SERVICE vacuum supply to EGR V.R. solenoid. INSPECT vacuum hoses, connections, and vacuum reservoirs leading to intake manifold as necessary.
HJ31 CHECK VACUUM HOSE TO EGR VALVE
Key off.
Carefully check vacuum hose between EGR valve and EGR V.R. solenoid for obstructions, cracks, loose connection, blockage, kinks, leaks, icing, etc.
Is vacuum hose OK?
Yes No
GO to HJ32 . SERVICE or REPLACE vacuum hose as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ32 CHECK EGR VALVE FUNCTION
Key off.
Remove and plug the vacuum hose connected to EGR valve.
Disconnect the Idle Air Control (IAC) solenoid.
Key on, engine running.
Access RPM PID with a Scan Tool or install a tachometer, Rotunda 059-00010 or equivalent.
With engine at idle, slowly apply 5-10 in-Hg (17-34 kPa) vacuum to the EGR valve with a hand vacuum pump while observing rpm.
Does the idle speed drop more than a 100 rpm with full vacuum applied and return to normal (+/- 25 rpm) after the vacuum is removed?
Yes No
RECONNECT IAC solenoid. GO to HJ33 . SERVICE or REPLACE DAMAGED EGR valve. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ33 CHECK EGRVP PID WHILE EXERCISING EGR VALVE
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Slowly apply 5-10 in-Hg (17-34 kPa) vacuum to the EGR valve with a hand vacuum pump while observing EGRVP PID voltage.
Note: The EGR Valve Position sensor voltage with the EGR valve closed is between 0.24 and 0.67 volts.
Does the EGRVP PID voltage indicate 3.0 volts or greater with full vacuum applied?
Yes No
GO to HJ34 . REPLACE damaged EGR V.P. sensor. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ34 CHECK EGR VACUUM REGULATOR SOLENOID FUNCTION
Key off.
Connect the EGR valve vacuum hose to a vacuum gauge.
Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Install breakout box, reconnect PCM.
Key on, engine running.
Jumper Test Pin 47 (EVR) to Test Pin 51 or 103 (PWR GND) at the breakout box.
Does the vacuum gauge indicate a vacuum of 5.0 in-Hg (17 kPa) minimum at the EGR valve?
Yes No
GO to HJ35 . REPLACE damaged EGR V.R. solenoid. RECONNECT all components. RERUN Quick Test .
HJ35 CHECK FOR INTERMITTENT EGR V.R. SOLENOID AND CIRCUIT
Key on, engine running.
Jumper connected from Step HJ34 .
Vacuum should read greater than 5.0 in-Hg (17 kPa).
Observe the EGR valve vacuum to drop as an indication of a fault while performing the following:
Lightly tap on EGR V.R. solenoid.
Wiggle the solenoid connector and vacuum lines.
Grasp the solenoid vehicle harness and wiggle wires between solenoid and PCM.
Is a fault indicated?
Yes No
ISOLATE fault and SERVICE as necessary. RECONNECT all components. RERUN Quick Test . Unable to duplicate and/or identify fault at this time. GO to Pinpoint Test Step Z1 with the following data: EGRVP and EGRVR PIDs and list of possible causes.
HJ40 DTC P0402: OUTPUT ALL DIAGNOSTIC TROUBLE CODES (DTC)
Diagnostic Trouble Code (DTC) P0402 indicates that self-test has detected EGR flow.
Possible causes:
Non-seated EGR valve.
Damaged EGR valve.
Damaged EGR Valve Position (EGR V.P.) sensor.
Plugged or pinched EGR valve vacuum hose.
Plugged or iced EGR Vacuum Regulator (EGR V.R.) solenoid vent.
EVR circuit shorted to GND.
Damaged EGR Vacuum Regulator solenoid.
Damaged PCM.
Output all Diagnostic Trouble Codes (DTCs).
Is DTC P1409 present?
Yes No
GO to HJ20 . GO to HJ41 .
HJ41 CHECK EGRVP PID VOLTAGE WITH ENGINE OFF
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Note: The EGR Valve Position sensor voltage with the EGR valve closed is between 0.24 and 0.67 volt.
Does the EGRVP PID indicate a voltage greater than 0.67 volt?
Yes No
The EGRVP PID is indicating a voltage greater than the acceptable closed EGR valve voltage. GO to HJ42 . GO to HJ44 .
HJ42 CHECK EGRVP PID VOLTAGE WITH EGR VACUUM HOSE DISCONNECTED
Key on, engine off.
Access EGRVP PID with a Scan Tool.
Disconnect vacuum hose at EGR valve to allow trapped vacuum to vent if any.
Does the EGRVP PID voltage drop to an acceptable level between 0.24 and 0.67 volts?
Yes No
INSPECT EGR Vacuum Regulator solenoid hoses for a pinched, plugged or damaged hose. If OK, REPLACE EGR Vacuum Regulator solenoid. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . GO to HJ43 .
HJ43 EXERCISE EGR VALVE WITH ENGINE RUNNING
Key off.
EGR valve vacuum hose disconnected.
Connect a hand vacuum pump at the EGR valve.
Start engine.
Access EGRVP PID with a Scan Tool.
Exercise EGR valve by applying 5-10 in-Hg (17-34 kPa) vacuum to the EGR valve and releasing it. Repeat this several times, and in between each time, tap on EGR valve lightly with a small solid object (screwdriver handle) in an attempt to dislodge contamination from valve if any.
Does the EGRVP PID voltage drop to an acceptable level between 0.24 and 0.67 after several attempts at dislodging foreign material?
Yes No
DTC P0402 was the result of EGR valve binding or foreign contamination. SERVICE as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test. REMOVE EGR valve and EGR Valve Position sensor and INSPECT closely for damage. If none is evident, REPLACE EGR valve. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . If DTC is still present, REPLACE EGR Valve Position sensor.
HJ44 CHECK EGRVP PID VOLTAGE WITH ENGINE RUNNING
Key on, engine running.
Access EGRVP PID with a Scan Tool.
Note: The EGR Valve Position sensor voltage with the EGR valve closed is between 0.24 and 0.67 volts.
Does the EGRVP PID indicate a voltage greater than 0.67 volts with the engine running at idle?
Yes No
This indicates that the fault is in the vacuum control side of the EGR system. GO to HJ45 . The fault that produced DTC P0402 is intermittent. GO to HJ46 .
HJ45 CHECK EGR VACUUM REGULATOR SOLENOID
Key off.
Remove the EGR Vacuum Regulator solenoid vent cap and inspect the vent for plugging.
Verify that the EGR Vacuum Regulator solenoid hoses are installed and routed properly.
Are the solenoid vacuum hoses and vent OK?
Yes No
REPLACE the EGR Vacuum Regulator solenoid. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . SERVICE as necessary. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ46 CHECK EGR SYSTEM FOR INTERMITTENT FAULT
Key off.
Disconnect EGR valve vacuum hose.
Connect a hand vacuum pump at the EGR valve.
Start engine.
Access EGRVP PID with a Scan Tool.
Exercise EGR valve by applying 5-10 in-Hg (17-34 kPa) vacuum to the EGR valve and releasing it. Repeat this several times. On a normal functioning system, the EGRVP PID voltage will be between 0.24 and 0.67 volt each time the vacuum is released. As an indication of a fault, look for the voltage to hang up above 0.67 volt after vacuum is released.
Does the EGRVP PID voltage drop to an acceptable level, between 0.24 and 0.67 volt each time the vacuum is released?
Yes No
RECONNECT EGR valve vacuum hose. GO to HJ47 . ISOLATE fault and SERVICE as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test .
HJ47 CHECK FOR INTERMITTENT EGR VALVE POSITION SENSOR AND EGR VACUUM REGULATOR SOLENOID
Key on, engine running.
Access EGRVP PID with a Scan Tool. The PID voltage should read between 0.24 and 0.67 volt with engine at idle.
Observe the EGRVP PID voltage to go greater than 0.67 volt as an indication of a fault while performing the following:
Lightly tap on the EGR V.P. sensor and connector.
Grasp the EGR V.R. sensor vehicle harness and wiggle wires between the sensor and PCM.
Lightly tap on the EGR V.P. solenoid vehicle harness connector.
Grasp the EGR V.R. solenoid vehicle harness and wiggle wires between the solenoid and PCM.
Is a fault indicated?
Yes No
ISOLATE fault and SERVICE as necessary. RECONNECT all components. COMPLETE PCM Reset to clear DTCs (REFER to Section 2A, Powertrain Control Module (PCM) Reset ). RERUN Quick Test . Unable to duplicate and/or identify fault at this time. GO to Pinpoint Test Step Z1 with the following data: EGRVP and EGRVR PIDs and list of possible causes.
