Test W: Exhaust Gas Recirculation (EGR) Systems
PINPOINT TEST W: EXHAUST GAS RECIRCULATION (EGR) SYSTEMSFlow Chart:
This pinpoint test is intended to diagnose the following:
- harness circuits: VPWR, VREF, EGR, EGRMC and SIGRTN
- EGR actuator
- powertrain control module (PCM)
EGR Actuator Connector
EGR Actuator Connector:
PCM Connector
PCM Connector:
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W1 : DTCs P0401, P0402, P0403, P0404, P0405, P0406, P1335 and P1408: PRELIMINARY DIAGNOSIS
NOTE: Diagnose DTCs P0234 or P0299, alone or in combination, before proceeding with this pinpoint test.
- Carry out a visual inspection.
- Retrieve and record any continuous and on-demand DTCs.
- Record the freeze frame data.
- Clear the DTCs.
- Carry out the self-test.
- Are any DTCs retrieved?
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W2 : DTCs P0401, P0402, P0404 or P1408: CHECK FOR OTHER DTCS
NOTE: Visually inspect the vehicle for aftermarket accessories and performance modifications (air filter, exhaust system, intake system, performance chip, turbocharger). Refer to Description and Operation, Electronic Engine Control (EEC) System, Modifications to OBD Vehicles. Electronic Engine Control (EEC) System
- Carry out the self-test.
- Are other DTCs present?
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W3 : CARRY OUT THE EGR SYSTEM TEST
- Engine at normal operating temperature.
- Ignition ON, engine OFF.
- Access the PCM and the EGR System Test.
- Carry out the EGR System Test while following the directions on the scan tool. 8. Exhaust Gas Recirculation (EGR) System Test
- Did the EGR System Test pass all tests?
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W4 : DTC P0403: CHECK THE VPWR CIRCUIT FOR VOLTAGE
- Ignition OFF.
- EGR Actuator connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage greater than 11 V?
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W5 : CHECK THE EGRMC CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage greater than 0.2 V?
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W6 : CHECK THE EGRMC CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- Is the resistance greater than 10 kOhm?
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W7 : CHECK THE EGRMC CIRCUIT FOR AN OPEN
- Measure the resistance between:
- Is the resistance less than 5 Ohm?
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W8 : CHECK THE EGR ACTUATOR
- Measure the resistance between:
- Is the resistance between 4 Ohm - 10 Ohm?
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W9 : DTC P1335: CHECK THE EGRVP PID VOLTAGE
NOTE: DTC P1335 is set when the EGR closed position voltage is greater than 1.20 volts at initial ignition ON which can be caused by excessive carbon buildup on the EGR valve.
- Ignition ON, engine OFF.
- Access the PCM and monitor the EGRVP PID.
- Is the EGRVP PID voltage under 1.20 volts?
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W10 : DTC P0405: CHECK THE VREF CIRCUIT FOR VOLTAGE
- Ignition OFF.
- EGR Actuator connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage between 4.5 V - 5.5 V?
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W11 : CHECK THE EGR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- PCM connector disconnected.
- Measure the resistance between:
- Is the resistance greater than 10 kOhm?
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W12 : CHECK THE EGR CIRCUIT FOR AN OPEN
- Measure the resistance between:
- Is the resistance less than 5 Ohm?
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W13 : CHECK THE EGR ACTUATOR
- Measure the resistance between the EGR actuator pins, component side as follows:
EGR ACTUATOR CONNECTOR
EGR Actuator Connector:
- Are the resistances within specifications?
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W14 : DTC P0406: CHECK FOR DTC P0405
- Ignition OFF.
- EGR Actuator connector disconnected.
- The EGR actuator is disconnected to simulate the opposite DTC.
- Ignition ON, engine OFF.
- Carry out the self-test.
- Is DTC P0405 present?
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W15 : CHECK THE EGR CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage less than 0.2 V?
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W16 : CHECK THE SIGRTN CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between:
- Are the resistances less than 5 ohms?
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W17 : CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
