EGR System Monitor
OBD System Description - EGR System MonitorEGR Insufficient Flow
DTC Description / Detecting Condition / Confirmation Procedure
P0401 refer to [DTC P0401: Exhaust Gas Recirculation (EGR) Flow Insufficient]. P0401
Monitor Strategy Description
This diagnostic will determine if there is a reduction in EGR Flow.
Malfunction Criteria
Filtered MAP change (Expected - Actual) > See table below.
The associated change in MAP is compared with a threshold from RPM vs. Barometric Pressure table. > 0 kPa (passing)
The results are statistically filtered (EWMA) and compared to a decision limit. DTC is set when the filtered result exceeds the decision limit. > -1 kPa (failing)
Enable Conditions
EGR Flow Diag Enable Conditions
Disabling Faults Present = FALSE boolean
AND EGR Flow test Complete this key cycle = FALSE boolean
AND EGR Flow test abort requested = FALSE boolean
AND EGR Engine Conditions Met = TRUE boolean
AND EGR Flow Transient Conditions Met = TRUE boolean
AND EGR Flow Stability Conditions Met = TRUE boolean
AND Off Board control requested = FALSE boolean
Engine Conditions
EGR Flow Test Delay = FALSE boolean
AND EGR Flow test abort = FALSE boolean
AND EGR Hardware Conditions Met = TRUE boolean
AND IAT > 2.75 °C
AND IAT < 80 °C
AND Vehicle Speed > 11 mph
AND Throttle Position < 1.001%
AND Barometric Pressure > 72 kPa
AND Engine Speed > 1200 rpm
Stability Conditions
EGR Engine Conditions Met = TRUE boolean
AND EGR Flow Transient Conditions Met = TRUE boolean
AND EGR Flow Diag Enabled = TRUE boolean
AND EGR Position < 1.001%
AND Altitude Compensated MAP >= 10 kPa
AND Altitude Compensated MAP <= 36 kPa (For AT)
AND Altitude Compensated MAP <= 39 kPa (For MT)
AND Engine Speed >= 1300 rpm
AND Engine Speed <= 2900 rpm (For AT)
AND Engine Speed <= 3000 rpm (For MT)
AND Delta MAP < 1 kPa
Transient Conditions
EGR Engine Conditions Met = TRUE boolean
AND {(DFCO status condition met = TRUE boolean
AND KbEGRF_EnblTstInDFCO) = TRUE boolean
OR (DFCO status condition met = FALSE boolean
AND KbEGRF_EnblTstNotInDFCO)} = TRUE boolean
AND Current AC Clutch state = Previous state enum
AND Torque Fuel Ratio Correction enabled = FALSE boolean
AND Current TCC state = Previous state enum
AND Delta Idle Airflow < 14.9994 g/s
Time required
Test runs once per key cycle depending on drive cycle.
EGR Excessive Flow during Crank
DTC Description / Detecting Condition / Confirmation Procedure
P0402 refer to [DTC P0402: Exhaust Gas Recirculation (EGR) Flow Excessive]. P0402
Monitor Strategy Description
Detects an EGR open to a large open position during crank.
Malfunction Criteria
EGR Raw Position > 70.0012%
Enable Conditions
Engine State = CRANK enum
AND Off Board control requested = FALSE boolean
AND Ignition Voltage >= 10 V
AND Ignition Voltage <= 16 V
Time required
Test runs during crank 3 seconds required for failure
EGR Open Valve Position Error
DTC Description / Detecting Condition / Confirmation Procedure
P0404 refer to [DTC P0404: Exhaust Gas Recirculation (EGR) Open Position Performance]. P0404
Monitor Strategy Description
This DTC will detect an open valve position error.
Malfunction Criteria
Current - Commanded EGR > 14.9994%
Enable Conditions
Engine State = RUN enum
AND EGR Flow Conditions Met = FALSE boolean
AND Off Board control requested = FALSE boolean
AND EGR Open Valve Disabling Faults = FALSE boolean
AND EGR Hardware Conditions Met = TRUE boolean
AND IAT > 2.75 °C
AND IAT < 80 °C
AND IAT >= 3 °C
ZONE 1: Desired EGR Position > 50%
ZONE 2: Desired EGR Position < 50%
Time required
Detection Time
0.38 seconds failure out of 0.63 seconds sample period
Continuous Monitoring every 125. ms loop time
Detection Samples
3 test failures within 40 test samples at 125. ms loop time
EGR Closed Valve Pintle Error
DTC Description / Detecting Condition / Confirmation Procedure
P042E refer to [DTC P042E: Exhaust Gas Recirculation (EGR) Closed Position Performance]. P042E
Monitor Strategy Description
This DTC will detect an EGR valve that will not close completely.
Malfunction Criteria
Current - Learned Low Raw EGR Position > 10.0006%
Enable Conditions
Engine State = RUN enum
AND Off Board control not requested = FALSE boolean
AND Closed Valve Disabling faults not present = FALSE boolean
AND EGR Hardware Conditions Met = TRUE boolean
AND IAT > 2.75 °C
AND IAT < 80 °C
AND IAT >= 3 °C
AND Desired EGR Position = 0%
Time required
Detection Time
5.00 seconds failure out of 5 seconds
Continuous Monitoring every 125. ms loop time
Detection Samples
40 test failures within 40 test samples at 125. ms loop time
NOTE:
Test must fail 3 times each time separated by at least a 5 sec. period with EGR > 30%
EGR Pintle Position Sensor Circuit Low
DTC Description / Detecting Condition / Confirmation Procedure
P0405 refer to [DTC P0405: Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage]. P0405
Monitor Strategy Description
This DTC will detect open/short low circuit or sensor.
Malfunction Criteria
EGR position signal < 1.9989%
Enable Conditions
Engine State = RUN enum
AND Ignition Voltage >= 11.7002 V
AND Ignition Voltage <= 16 V
Time required
Detection Time
10.00 seconds failure out of 10. seconds sample period
Continuous Monitoring every 125. ms loop time
EGR Pintle Position High Voltage
DTC Description / Detecting Condition / Confirmation Procedure
P0406 refer to [DTC P0406: Exhaust Gas Recirculation (EGR) Position Sensor Circuit High Voltage]. P0406
Monitor Strategy Description
This DTC will detect short high circuit or sensor.
Malfunction Criteria
EGR position signal > 98.0011%
Enable Conditions
Engine State = RUN enum
AND Ignition Voltage >= 11.7002 V
AND Ignition Voltage <= 16 V
Time required
Detection Time
10.00 seconds failure out of 10. seconds sample period
Continuous Monitoring every 125. ms loop time
MODE $06 Data
EGR Monitor Bank 1:
Refer to [MODE $06 Diagnostic Description]. Mode 6 Data