Test Procedure

HH1 DTCS P0405 AND P1400: DETERMINE THE PRESENT DPFEGR PID VOLTAGE

Key in ON position.
Access the PCM and monitor the DPFEGR PID.

Is the voltage less than 0.2 V?

Yes	No
GO to HH2.	GO to HH10.

HH2 INDUCE OPPOSITE DPFEGR SENSOR SIGNAL

Key in OFF position.
ESM connector disconnected.
Key in ON position.
Access the PCM and monitor the DPFEGR PID.

Is the voltage between 4 V - 6 V?

Yes	No
INSTALL a new ESM.	GO to HH3.

HH3 CHECK THE DPFEGR CIRCUIT FOR A SHORT TO SIGRTN OR GND IN THE HARNESS

Key in OFF position.
PCM connector disconnected.

Measure the resistance between:

(+) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
DPFEGR	SIGRTN

Measure the resistance between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
DPFEGR	Negative terminal

Is the resistance greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	REPAIR the short circuit in question.

HH4 DTCS P0406 AND P1401: DETERMINE THE PRESENT DPFEGR PID VOLTAGE

Key in ON position.
Access the PCM and monitor the DPFEGR PID.

Is the voltage greater than 4 V?

Yes	No
GO to HH5.	GO to HH10.

HH5 CHECK THE VREF VOLTAGE TO ESM

Key in OFF position.
ESM connector disconnected.
Key in ON position.

Measure the voltage between:

(+) ESM Connector, Harness Side	(-) Vehicle Battery
VREF - Pin 2	Negative terminal

Is the voltage between 4 V - 5.5 V?

Yes	No
GO to HH6.	REPAIR the open circuit.

HH6 CHECK THE DPFEGR CIRCUIT FOR A SHORT TO POWER

Key in OFF position.
PCM connector disconnected.
Key in ON position.

Measure the voltage between:

(+) ESM Connector, Harness Side	(-) Vehicle Battery
DPFEGR - Pin 5	Negative terminal

Is the voltage less than 1 V?

Yes	No
GO to HH7.	REPAIR the short circuit.

HH7 CHECK THE DPFEGR CIRCUIT FOR A SHORT TO VREF

Key in OFF position.

Measure the resistance between:

(+) PCM Connector, Harness Side	(-) PCM Connector, Harness Side
VREF	DPFEGR

Is the resistance greater than 10K ohms?

Yes	No
GO to HH8.	REPAIR the short circuit.

HH8 CHECK THE DPFEGR AND SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS

Measure the resistance between:

(+) PCM Connector, Harness Side	(-) ESM Connector, Harness Side
DPFEGR	DPFEGR - Pin 5
SIGRTN	SIGRTN - Pin 6

Are the resistances less than 5 ohms?

Yes	No
GO to HH9.	REPAIR the open circuit.

HH9 INDUCE THE OPPOSITE DPFEGR SENSOR VOLTAGE

PCM connector connected.

Connect a 5 amp fused jumper wire between the following:

Point A ESM Connector, Harness Side	Point B ESM Connector, Harness Side
DPFEGR - Pin 5	SIGRTN - Pin 6

Key in ON position.
Access the PCM and monitor the DPFEGR PID.

Is the voltage less than 0.1 V?

Yes	No
INSTALL a new ESM.	INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .

HH10 CARRY OUT A THOROUGH WIGGLE TEST ON THE ESM HARNESS

Access the PCM and monitor the DPFEGR PID.
Wiggle, shake, and bend small sections of the wiring harness while working from the sensor to the PCM.

Is there any change in the voltage reading, or is a concern found?

Yes	No
REPAIR as necessary.	Unable to duplicate or identify the fault at this time. GO to PINPOINT TEST Z STEP 1 .

HH11 DTC P0402: CHECK THE VREF VOLTAGE TO THE ESM

NOTE: Diagnose and repair all circuit fault DTCs before diagnosing range/performance or flow concerns. For circuit fault DTC diagnosis, refer to the POWERTRAIN DTC CHARTS AND DESCRIPTIONS - GASOLINE MODELS .

Key in OFF position.
ESM connector disconnected.
Key in ON position.

Measure the voltage between:

(+) ESM Connector, Harness Side	(-) Vehicle Battery
VREF - Pin 2	Negative terminal

Is the voltage between 4.5 V - 5.5 V?

Yes	No
GO to HH12.	GO to PINPOINT TEST C STEP 1 .

HH12 SIMULATE THE DPFE SENSOR SIGNAL WITH A VACUUM PUMP

Disconnect the downstream DPFE sensor port hose at the ESM.
Verify hose and port is clear and free of obstructions.
Connect a vacuum pump to the downstream DPFE sensor port.
Key in ON position.
Access the PCM and monitor the DPFEGR PID.
Apply 27 - 30 kPa (8 - 9 in Hg) vacuum to the DPFE sensor and hold for 10 seconds.
Quickly release vacuum.
- The DPFEGR PID voltage must be between 0.2 and 1.3 volt with the key ON and no vacuum applied.
- The DPFEGR PID voltage must increase to greater than 4 volts with the vacuum applied.
- The DPFEGR PID must drop to less than 1.5 volts in less than 3 seconds when the vacuum is released.

Does the DPFEGR PID voltage indicate a fault in the DPFE sensor?

Yes	No
INSTALL a new ESM.	GO to HH13.

HH13 INSPECT THE EVR SOLENOID VENT FOR BLOCKAGE

NOTE: When the EGR valve is closed, the EVR solenoid vacuum is vented through the solenoid vent to the atmosphere. A plugged EVR solenoid vent will not allow EGR vacuum to vent to atmosphere.

EVR vacuum hose disconnected.
Remove the EVR solenoid vent cap (if removable).
Remove the filter and inspect for blockage, or in some cases, icing.
Connect a hand vacuum pump to the EVR source port.
Apply 34 to 51 kPa (10 to 15 in Hg) vacuum.

Does the EVR solenoid vacuum bleed off?

Yes	No
GO to HH14.	REPAIR the vent, or if not repairable, INSTALL a new ESM assembly.

HH14 CHECK THE EGR VALVE FOR CARBON BUILD-UP

Remove the ESM.
Visually inspect the EGR valve and valve seat for proper seating, carbon build-up and debris.

Is a concern present?

Yes	No
REPAIR as necessary.	Unable to duplicate or identify the fault at this time.

HH15 DTC P0401: CARRY OUT THE KOER SELF-TEST

NOTE: Diagnose and repair all circuit fault DTCs before diagnosing range/performance or flow concerns.

Carry out the KOER self-test.

Is DTC P1408 present?

Yes	No
GO to HH16.	GO to HH17.

HH16 DTC P1408: CHECK THE VREF VOLTAGE TO THE ESM

Key in OFF position.
ESM connector disconnected.
Key in ON position.

Measure the voltage between:

(+) ESM Connector, Harness Side	(-) Vehicle Battery
VREF - Pin 2	Negative terminal

Is the voltage between 4.5 V - 5.5 V?

Yes	No
GO to HH17.	GO to PINPOINT TEST C STEP 1 .

HH17 CHECK THE EVR SOLENOID VACUUM

ESM connector connected.
Disconnect the EVR vacuum source hose.
Connect a vacuum gauge to the EVR vacuum source hose.
Key on engine running.
Monitor the vacuum gauge.

Is the manifold vacuum greater than 34 kPa (10 in-Hg)?

Yes	No
GO to HH18.	REPAIR as necessary.

HH18 SIMULATE THE DPFE SENSOR SIGNAL WITH A VACUUM PUMP

Key in OFF position.
Disconnect the downstream DPFE sensor port hose at the ESM.
Verify hose and port is clear and free of obstructions.
Connect a vacuum pump to the downstream DPFE sensor port.
Key in ON position.
Access the PCM and monitor the DPFEGR PID.
Apply 27 - 30 kPa (8 - 9 in Hg) vacuum to the DPFE sensor and hold for 10 seconds.
Quickly release vacuum.
- The DPFEGR PID voltage must be between 0.2 and 1.3 volt with the key ON and no vacuum applied.
- The DPFEGR PID voltage must increase to greater than 4 volts with the vacuum applied.
- The DPFEGR PID must drop to less than 1.5 volts in less than 3 seconds when the vacuum is released.

Does the DPFEGR PID voltage indicate a fault in the DPFE sensor?

Yes	No
INSTALL a new ESM.	CONNECT all the hoses. GO to HH19.

HH19 CHECK THE EVR SOLENOID OPERATION

Key on engine running.
Engine at normal operating temperature.
Allow the engine idle to stabilize.
Access the PCM and monitor the RPM PID.
Access Output State Control.
Increase the EVR duty cycle while monitoring the RPM PID.

Does the RPM decrease or the engine stall as the EVR duty cycle is increased?

Yes	No
Unable to duplicate or identify the fault at this time. CHECK for the presence of carbon build-up in the EGR passage.	GO to HH20.

HH20 CHECK FOR THE PRESENCE OF CARBON BUILD-UP IN THE EGR PASSAGE

NOTE: In certain vehicle applications, carbon build-up may occur downstream of the ESM. An inspection is required to make sure the passage in the upper intake manifold plenum chamber behind the ESM is open to allow exhaust gas flow.

Key in OFF position.
Remove the ESM. For additional information, REFER to ELECTRONIC ENGINE CONTROLS .
Disconnect the air inlet tube from the throttle body. For additional information, REFER to INTAKE AIR DISTRIBUTION AND FILTERING .
Prop open the throttle body.
Apply regulated shop air to the EGR port at the location where the ESM attaches to the upper intake manifold.

Is a restriction concern present?

Yes	No
CLEAN the EGR port as necessary and reinstall the ESM.	INSTALL a new ESM.

HH21 DTCS P0403 AND P1409: CHECK THE EVR SOLENOID OPERATION

Key on engine running.
Engine at normal operating temperature.
Allow the engine idle to stabilize.
Access the PCM and monitor the RPM PID.
Access Output State Control.
Increase the EVR duty cycle while monitoring the RPM PID.

Does the RPM decrease or the engine stall as the EVR duty cycle is increased?

Yes	No
Unable to duplicate or identify the fault at this time. GO to PINPOINT TEST Z STEP 1 .	GO to HH22.

HH22 CHECK THE VPWR VOLTAGE TO THE EVR SOLENOID

Key in OFF position.
ESM connector disconnected.
Key in ON position.

Measure the voltage between:

(+) ESM Connector, Harness Side	(-) Vehicle Battery
VPWR - Pin 4	Negative terminal

Is the voltage greater than 10.5 V?

Yes	No
GO to HH23.	REPAIR the open circuit.

HH23 CHECK THE EVR SOLENOID COIL RESISTANCE

Key in OFF position.

Measure the resistance between:

(+) ESM Connector, Component Side	(-) ESM Connector, Component Side
VPWR - Pin 4	EGRVR

Is the resistance between 26 ohms - 40 ohms?

Yes	No
GO to HH24.	INSTALL a new ESM.

HH24 CHECK THE EVR CIRCUIT FOR AN OPEN IN THE HARNESS

PCM connector disconnected.

Measure the resistance between:

(+) ESM Connector, Harness Side	(-) PCM Connector, Harness Side
EVR - Pin 1	EVR

Is the resistance less than 5 ohms?

Yes	No
GO to HH25.	REPAIR the open circuit.

HH25 CHECK THE EVR CIRCUIT FOR A SHORT TO POWER IN THE HARNESS

Key in ON position.

Measure the voltage between:

(+) PCM Connector, Harness Side	(-) Vehicle Battery
EVR	Negative terminal

Is the voltage less than 1 V?

Yes	No
GO to HH26.	REPAIR the short circuit.

HH26 CHECK THE EVR CIRCUIT FOR A SHORT TO GND IN THE HARNESS

Key in OFF position.

Measure the resistance between:

(+) PCM Connector, Harness Side	(-)
EVR	Ground

Is the resistance greater than 10K ohms?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	REPAIR the short circuit.

HH27 EGR DIAGNOSIS BY SYMPTOM: CHECK FOR EGR FLOW WITH THE EVR VACUUM HOSE DISCONNECTED AND PLUGGED

NOTE: Carry out the KOER self-test. Repair any other DTCs.

Possible causes for EGR flow at idle with no related DTCs:
- EGR valve not fully seating.
- EVR solenoid vent restricted.
- Damaged EVR solenoid.
Disconnect and plug the EVR vacuum source hose.
Key in ON position.
Access the PCM and monitor the DPFEGR PID.
Record the PID voltage.
Key on engine running.
With the engine at idle, observe the DPFEGR PID voltage.
Compare to engine OFF voltage.
An increase in DPFEGR PID voltage at idle indicates EGR flow.

Is the idle DPFEGR PID voltage greater than 0.15 volt when compared to the KOEO DPFEGR PID voltage?

Yes	No
REMOVE and INSPECT the ESM for signs of contamination, unusual wear, carbon deposits, binding or other damage. REPAIR as necessary. If no concerns are present, INSTALL a new ESM.	INSPECT the EVR solenoid vent for blockage. To continue symptom diagnosis, REFER to STEP 3: NO DTC(S) PRESENT SYMPTOM CHARTS .