EGR System Monitor
OBD System Description - EGR System MonitorExhaust Gas Recirculation Flow
DTC
Limits:
P0400 (EGR Flow limits) Refer to DTC P0400: Exhaust Gas Recirculation (EGR) Flow Incorrect. P0400
Permanent:
P0401 (Permanent EGR Flow) Refer to DTC P0401: Exhaust Gas Recirculation (EGR) Flow Insufficient. P0401
Leakage:
P0402 (Leakage in EGR System) Refer to DTC P0402: Exhaust Gas Recirculation (EGR) Flow Excessive P0402
MONITOR STRATEGY DESCRIPTION
This function is used for functional diagnosis of the EGR system and to adapt the EGR valve. The strategy is based on manifold pressure measurements during fuel cut off conditions while the EGR valve is activated at different positions. This strategy operates once per driving cycle when conditions to activate the function are fulfilled. If fuel cut off conditions do not last long enough, it is possible to run the strategy in two steps. One step is the preferred solution. At the moment, the two steps solution is not validated. At the end, a filtered adaptive coefficient can be calculated to adapt the EGR valve.
For diagnosis, three symptoms can create a EGR error:
- Constant flow in the system
- Leakage in the EGR system
- Too much or not enough EGR flow in the system
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Limits:
Calibrated intake manifold pressure difference between pressure with EGR valve opened (second position) and pressure with EGR valve closed / first difference between MAP referenced values to detect leak EGR valve) < 0.71997
Or
Calibrated intake manifold pressure difference between pressure with EGR valve opened (second position) and pressure with EGR valve closed / Referenced intake manifold pressure for measurements when EGR valve is open > 3.00
And
Intake manifold pressure for measurements when EGR valve is closed < 300 hPa
Remark:
Maximum duration time of 6 sec. is needed to complete the EGR diagnosis
Permanent:
Referenced intake manifold pressure difference between pressure with EGR valve opened (first position) and pressure with EGR valve closed < 19.98 hPa
And
Referenced intake manifold pressure difference between pressure with EGR valve opened (second position) and pressure with EGR valve closed < 19.98 hPa
Remark:
Maximum duration time of 6 sec. is needed to complete the EGR diagnosis.
Leakage:
Switch between EGR valve leakage detection algorithms = true
And
Referenced intake manifold pressure difference between pressure with EGR valve opened (first position) and pressure with EGR valve closed < 0 hPa
And
Referenced intake manifold pressure difference between pressure with EGR valve opened (second position) and pressure with EGR valve closed > 5,434 hPa
Or
Switch between EGR valve leakage detection algorithms = OFF
And
Referenced intake manifold pressure difference between pressure with EGR valve opened (first position) and pressure with EGR valve closed > 35.07 hPa
And
Previous adaptive factor for EGR valve adaptation *Mode 6 variable for EGR system diagnosis < 0.57001
Or
Intake manifold pressure for measurements when EGR valve is closed > 300 hPa
And
Calibration bit to choose if valve leakage and min/max EGR flow limits are detected when intake manifold pressure is too high with closed EGR valve = 1
Remark:
Maximum duration time of 6 sec. is needed to complete the EGR diagnosis.
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Limits:
Enable Conditions:
- No EGR error
- 1,376 rpm < RPM < 2,720 rpm
- -256 rpm/s < Moving Mean value of engine speed gradient < 192 rpm/s
- MAP > 150 hPa
- 2.341 TPS < Actual TPS value < Table (Up to 13.122 TPS)
- 10.968 V < Battery voltage < 15.640 V
- Air Temp. at the throttle body >= -15 degrees C
- Ambient pressure >= 740.04 hPa
- -704 rpm/s < Engine speed gradient < 288 rpm/s
Permanent:
Enable Conditions:
- No EGR error
- 1,376 rpm < RPM < 2,720 rpm
- -256 rpm/s < Moving Mean value of engine speed gradient < 192 rpm/s
- MAP > 150 hPa
- 2.341 TPS < Actual TPS value < Table (Up to 13.122 TPS)
- 10.968 V < Battery voltage < 15.640 V
- Air temperature at the throttle body >= -15 degrees C
- Ambient pressure >= 740.04 hPa
- -704 rpm/s < Engine speed gradient < 288 rpm/s
Leakage:
Enable Conditions:
- No EGR error
- 1,376 rpm < RPM < 2,720 rpm
- -256 rpm/s < Moving Mean value of engine speed gradient < 192 rpm/s
- MAP > 150 hPa
- 2.341 TPS < Actual TPS value < Table (Up to 13.122 TPS)
- 10.968 V < Battery voltage < 15.640 V
- Air Temp. at the throttle body >= -15 degrees C
- Ambient pressure >= 740.04 hPa
- -704 rpm/s < Engine speed gradient < 288 rpm/s
TIME LENGTH AND FREQUENCY
Limits:
Recurrence rate: 20 ms
Exhaust Gas Recirculation Control Circuit Diagnosis
DTC
P0403 Refer to DTC P0403: Exhaust Gas Recirculation (EGR) Solenoid Control Circuit. P0403
MONITOR STRATEGY DESCRIPTION
The EGR actuator is driven by the ECU via an output driver. The failure detection is done by ECU Hardware. The purpose of the diagnosis is to detect electrical faults as defined by OBD I requirements.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
After activation conditions are met, the diagnosis activation is delayed for a defined number of executions, to avoid the usage of wrong infrastructure information.
Error-symptoms and conditions: are defined to this diagnosis function as following
Short circuit to battery (SCP) (= SYM_0)
Short circuit to ground (SCG) (= SYM_1)
Open Load (OL) (= SYM_2)
Fail Time: 200 ms
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Ignition ON
Battery Voltage matches OBD conditions
10.968 V < Battery voltage < 16.046 V
SCP: Final EGR valve duty cycle < 0.751%
SCG: Final EGR valve duty cycle < 96.249%
OC: Final EGR valve duty cycle > 14.999%
Or
Final EGR valve duty cycle < 96.249%
TIME LENGTH AND FREQUENCY
Recurrence rate: 20 ms
Exhaust Gas Recirculation Control Unit Range/Performance
DTC
P0404 Refer to DTC P0404: Exhaust Gas Recirculation (EGR) Open Position Performance. P0404
MONITOR STRATEGY DESCRIPTION
This function is used for functional diagnosis of the EGR system and to adapt the EGR valve. The strategy is based on manifold pressure measurements during fuel cut off conditions while the EGR valve is activated at different positions. This strategy operates once per driving cycle when conditions to activate the function are fulfilled. If fuel cut off conditions do not last long enough, it is possible to run the strategy in two steps. One step is the preferred solution. At the moment, the two steps solution is not validated. At the end, a filtered adaptive coefficient can be calculated to adapt the EGR valve.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Position Controller Error:
No Error EGR position control
Integral duty cycle for EGR valve control >= 46.609%
=> Decrease the counter to indicate integral term is blocked in low or high limits about 1 Until counter reached 0
=> Error detected Adaptation outside range:
(Potentiometer low limit learnt > 1.758 V or Potentiometer low limit learnt < 0.161 V)
Timer for the adaptation of the lower mechanical valve stop >= 2 s
=> Error detected
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Position Controller Error:
Enable Conditions:
No EGR position control error has been detected
State variable for EGR control is closed the cleaning sequence is not in progress.
EGR valve closed
Adaptation outside range:
Enable Conditions:
No EGR position control error has been detected
State variable for EGR control is closed the cleaning sequence is not in progress.
EGR valve closed
TIME LENGTH AND FREQUENCY
Recurrence rate: 10 ms
Exhaust Gas Recirculation Sensor "A" Circuit Diagnosis
DTC
P0405 Refer to DTC P0405: Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage. P0405
P0406 Refer to DTC P0406: Exhaust Gas Recirculation (EGR) Position Sensor Circuit High Voltage. P0406
MONITOR STRATEGY DESCRIPTION
The purpose is to diagnose the analog input signal from EGR potentiometer to the main processor.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
P0405:
EGR Voltage < 0.054 V
P0406:
EGR Voltage > 4.8486 V
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Ignition ON
TIME LENGTH AND FREQUENCY
Recurrence rate: 20 ms
Mode $06 Data:
MODE $06 Data