Oxygen Sensor Monitor
OBD System Description - Oxygen Sensor MonitorO2 Sensor signals swapped Bank 1/2 Sensor 1
DTC
P0040 (B1S1 and B2S1) Refer to DTC P0040: HO2S Signals Swapped Bank 1 and 2 Sensor 1. P0040
MONITOR STRATEGY DESCRIPTION
This function was written for exhaust gas systems having two banks, where a sensor interchange cannot be avoided by hardware measures. In case the upstream sensors were interchanged it is expected that both lambda signals will drift from the set point in different directions and the lambda controllers achieve their maximum. A symptom can be detected if the lambda controller correction of one bank crosses the min threshold whereas the other one crosses the max threshold.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Limited value of lambda controller output 2 < -14.99%
Limited value of lambda controller output 1 > 14.99%
Or
Limited value of lambda controller output 2 > 14.99%
Limited value of lambda controller output 1 < -14.99%
AND
MAF integral for detection of interchanged upstream sensors > 130 g
SECONDARY PARAMETERS AND ENABLE CONDITIONS
This diagnostic is inhibited if any of the following DTC's are present:
Lambda Sensor Upstream error
Ignition coil error
misfire CARB A error
TIME LENGTH AND FREQUENCY
Recurrence rate: 100 ms
HO2S Slow Response / Frequency Bank 1 & 2 Sensor 1
DTC
P0133 (B1S1) Refer to DTC P0133: HO2S Slow Response Bank 1 Sensor 1. P0133
P0153 (B2S1) Refer to DTC P0153: HO2S Slow Response Bank 2 Sensor 1. P0153
MONITOR STRATEGY DESCRIPTION
The rich and lean dwell times and the check cycle counter are evaluated to check the oxygen sensor control frequency. These are also used to determine the catalyst efficiency.
In addition to this, the limits for the maximum rich and lean dwell times are derived from a map for each valid oxygen controller cycle.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Number of measured complete controller periods > 50 and
Total ratio between measured and max.
allowed rich time > 1.5937
or
Total ratio between measured and max.
allowed lean time > 1.5937
or
-0.5 >
(Total ratio between measured and max. allowed lean time - total ratio between measured and max. allowed rich time)
or
0.5 <
(Total ratio between measured and max. allowed lean time - total ratio between measured and max. allowed rich time)
frequency to low => error detected
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Enable Conditions:
IGK "ON"
512 rpm < RPM < 4,608 rpm
15 kg/h < MAF < 400 kg/h
ECT > 50.25 degrees C
Exhaust gas temperatures at the lambda sensor upstream > 399.97 degrees C
This diagnostic is inhibited if any of the following DTC's are present: TPS fault
ECT fault
CRK fault
IV fault
MAF fault
IGC fault
CAM fault
CPS fault
O2 upstream sensor fault
Misfire detected
TIME LENGTH AND FREQUENCY
Recurrence time: 10 ms
HO2 Sensor Circuit No activity detected
DTC
P0134 (B1S1) Refer to DTC P0134: HO2S Circuit Insufficient Activity Bank 1 Sensor 1. P0134
P0154 (B2S1) Refer to DTC P0154: HO2S Circuit Insufficient Activity Bank 2 Sensor 1. P0154
MONITOR STRATEGY DESCRIPTION
Sensor signal excursion:
Should the oxygen sensor internal resistance be too high, a too high contact resistance in the lambda sensor signal line exist, the signal voltage excursion may not be sufficient to guarantee correct lambda control.
In order to determine the signal fault, voltage excursion implausible, the difference in the measured voltage between rich and lean is compared to a calibratable threshold. Plausibility fault:
Due to possible oxygen sensor defects), the oxygen sensor may not provide the expected lean AFR signal level during an overrun fuel cut-off (PUC) condition.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Sensor signal excursion:
(Oxygen sensor rich voltage - Oxygen sensor lean voltage) < 0.22 V
Plausibility fault: Upstream Oxygen sensor voltage > 0.200 V For t > 400 ms
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Sensor signal excursion:
Enable Conditions:
No electrical fault on heater and signal line shall be present on the O2 sensor under test No lambda control in dead stop error
Number of lambda controller P-jumps > 30
The cycle time counters "lean" < 2 s
The cycle time counters "rich" < 2 s
Plausibility fault:
Enable Conditions:
- operative readiness of upstream oxygen sensor
- engine operating state = trailing throttle fuel cut off
- 20 g < air mass flow integral during pull cut off phase < 200 g
- Present heater state = lambda sensor heater power control
This diagnostic is inhibited if any of the following DTC's are present:
No O2 upstream error
No electrical canister purge valve failure
No injector error
No Mechanical failure on canister purge valve
No Misfire error
TIME LENGTH AND FREQUENCY
Sensor signal excursion:
Recurrence rate: 1,000 ms
Plausibility fault:
Recurrence rate: 20 ms
Heated Oxygen Sensor (HO2S) Low Voltage Bank 1 & 2 Sensor 2
DTC
P0137 (B1S2) Refer to DTC P0137: HO2S Circuit Low Voltage Bank 1 Sensor 2. P0137
P0157 (B2S2) Refer to DTC P0157: HO2S Circuit Low Voltage Bank 2 Sensor 2. P0157
MONITOR STRATEGY DESCRIPTION
This Diagnostic detects a SCG in the circuit or the Oxygen Sensor.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
HO2S Down Volts < 0.024 V
Internal resistance of downstream oxygen sensor (Released) < 25 Ohms
Fail Time > 2,000 ms
P0137 = Active
P0157 = Active
SECONDARY PARAMETERS AND ENABLE CONDITIONS
This diagnostic is inhibited if any of the following DTC's are present:
MAF fault
CRK fault
FSD fault
TPS fault
CPS fault
Enable Conditions:
IGN = ON
Lambda controller Trim = Active
MAF > 8 kg/h
Delay time for final diagnosis activation > 0.0 sec.
(Stabilization)
Diagnostic = Active 10.968 V < Battery voltage < 16.046 V
TIME LENGTH AND FREQUENCY
Recurrence rate: 100 ms
Heated Oxygen Sensor (HO2S) High Voltage Bank 1 & 2 Sensor 2
DTC
P0138 (B1S2) Refer to DTC P0138: HO2S Circuit High Voltage Bank 1 Sensor 2. P0138
P0158 (B2S2) Refer to DTC P0158: HO2S Circuit High Voltage Bank 2 Sensor 2. P0158
MONITOR STRATEGY DESCRIPTION
This Diagnostic detects a SCVB in the circuit or the Oxygen Sensor.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
HO2S Down Volts > 1.2 V
Fail Time > 2,000 ms
P0138 = Active
P0158 = Active
SECONDARY PARAMETERS AND ENABLE CONDITIONS
This diagnostic is inhibited if any of the following DTC's are present:
HO2S Circuit Faults
Enable Conditions:
IGN = ON
10.968V < Battery voltage < 16.046 V
TIME LENGTH AND FREQUENCY
Recurrence Rate: 100 ms
HO2S Slow Response Bank 1 & 2 Sensor 2 (rich/lean switch time error)
DTC
P0139 (Bank 1) Refer to DTC P0139: HO2S Slow Response Bank 1 Sensor 2. P0139
P0159 (Bank 2) Refer to DTC P0159: HO2S Slow Response Bank 2 Sensor 2. P0159
MONITOR STRATEGY DESCRIPTION
Changes in the dynamic behaviour of the monitor sensor can be detected by the recognition of the rich-lean switching time after fuel cut-off. After detection of the DFCO engine operating state, the rich-lean switching time of the lambda sensor is determined and weighted depending upon the mass air flow in the intake system. The functioning of the sensor is diagnosed by comparison of the mean value of the weighted switching time with a limit. The functioning is guaranteed in this test if the switching time is below the limit.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Number of valid switching times from rich to lean ≥ 2
And
Average of weighted Cycle counter for switching time determination > 1.296
This Diagnosis runs during the Unified Cycle to Illuminate the MIL.
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Enable Conditions:
IGK "ON"
ECT > 50.25 degrees C
20 km/h ≤ VS ≤ 150 km/h
CAT Temp. > 306.975 degrees C
TIME LENGTH AND FREQUENCY
Recurrence rate: 20 ms
Heated Oxygen Sensor Circuit B1S2
DTC
Rich not reached:
P0136 (B1S2) Refer to DTC P0136: HO2S Circuit Bank 1 Sensor 2. P0136
P0156 (B2S2) Refer to DTC P0156: HO2S Circuit Bank 2 Sensor 2. P0156
OL:
P0136 (B1S2) Refer to DTC P0136: HO2S Circuit Bank 1 Sensor 2. P0136
P0156 (B2S2) Refer to DTC P0156: HO2S Circuit Bank 2 Sensor 2. P0156
MONITOR STRATEGY DESCRIPTION
Active check:
The diagnosis monitors that a sufficient high lambda sensor voltage which is necessary for trim control and catalyst diagnosis can be reached. i.e. 0.55 V. As soon as the said threshold is exceeded the lambda sensor is recognized as able to provide a sufficiently large voltage signal and the end bit is set. To ensure a robust diagnosis result, a certain time in terms of a mass air integral threshold (1,000 g) is awaited, while the lambda control is in Closed Loop and fuel trim correction controller is activated.
In case that the lambda sensor has not provided a sufficient voltage value after the mass air flow integral threshold has elapsed, lambda control Closed Loop is stopped and an intrusive test is started by shifting the lambda set point to rich air fuel mixture (lambda = 0.8). At this time a fuel trim correction DTC (assigned to FSD, P2096-P2099) is entered due to opening Closed Loop (as malfunction indicator) and the intrusive operation is used to allocate the root cause for the insufficient lambda sensor voltage range. Reason is that in principle also a leak in the exhaust pipe may lead to a too lean mixture at the rear sensor position without the sensor having a malfunction. An additional precondition for the intrusive test is that a time after start has elapsed (300 sec.).
OL:
This Diagnosis is also to detect the Electrical malfunction open circuit in the signal lines
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Active check:
Mass airflow integral outside DFCO > 1,000 g
And
Mass airflow integral at rich A/F-mixture (lambda = 0.8) > 80 g
And
Monitoring sensor has not detected "rich"
==> rich voltage threshold: 0.55 V
OL:
Internal resistance of downstream oxygen sensor (Released)
> 60,000 Ohms
0.376 V < downstream Oxygen sensor voltage < 0.474 V for 3 sec.
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Active check:
This diagnostic is inhibited if any of the following DTC's are present:
CRK fault
CAM fault
MAF fault
O2 sensor fault
CPS fault
ECT fault
TPS fault
FSD fault
TPS/MAF fault
MAP fault
Misfire detected Enable Conditions:
- IGN = ON
- ECT > 75 degrees C
- Lambda sensor heater in controlled Open Loop (normal) operation which is active after dew point detection and an additional time interval of 25 sec.
- Closed Loop operation for lambda-controller and fuel trim correction controller
OL:
IGK "ON"
And HO2S Heater = ON
Exhaust gas temperatures at the lambda sensor downstream catalyst > 349.975 degrees C
Duration in which lambda probe voltage lies within voltage band to detect fault ≥ 3 s
Or Delay time for final diagnosis activation ≥DTC's s
This diagnostic is inhibited if any of the following DTC's are present:
O2 downstream sensor faults
TIME LENGTH AND FREQUENCY
Recurrence rate: 100 ms
Heated Oxygen Sensor Circuit No Activity Detected B1S2 & B2S2
DTC
Invalid signal after DFCO check:
P0140 (B1S2) Refer to DTC P0140: HO2S Circuit Insufficient Activity Bank 1 Sensor 2. P0140
P0160 (B2S2) Refer to DTC P0160: HO2S Circuit Insufficient Activity Bank 2 Sensor 2. P0160
Plausibility fault:
P0140 (B1S2) Refer to DTC P0140: HO2S Circuit Insufficient Activity Bank 1 Sensor 2. P0140
P0160 (B2S2) Refer to DTC P0160: HO2S Circuit Insufficient Activity Bank 2 Sensor 2. P0160
MONITOR STRATEGY DESCRIPTION
Plausibility fault (no activity lean):
During the DFCO-diagnosis the correct detecting of the lean phase through the downstream sensor will be checked.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Plausibility fault:
Downstream oxygen sensor voltage > 0.2 V
Fail Time > 1,000 ms
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Plausibility fault:
Enable Conditions:
IGK "ON"
No O2 downstream error
200 g > Air mass flow integral during pull cut off phase > 20 g
And
MAF integral out of DFCO in case of certain load threshold exceeded 1,200 g
This diagnostic is inhibited if any of the following DTC's are present:
MAF fault
MAP fault
O2 downstream sensor fault
CPS fault
FSD fault
PS/MAF fault
10.968 V < Battery voltage < 16.046 V
No misfire
TIME LENGTH AND FREQUENCY
Recurrence rate: 100 ms
HO2 sensor Circuit Sensor 1
DTC
OC:
P0130 (B1S1) Refer to DTC P0130: HO2S Circuit Bank 1 Sensor 1. P0130
P0150 (B2S1) Refer to DTC P0150: HO2S Circuit Bank 2 Sensor 1. P0150
Delayed upstream sensor readiness:
P0130 (B1S1) Refer to DTC P0130: HO2S Circuit Bank 1 Sensor 1. P0130
P0150 (B2S1) Refer to DTC P0150: HO2S Circuit Bank 2 Sensor 1. P0150
MONITOR STRATEGY DESCRIPTION
OC:
In order to determine the electrical fault, open circuit, the oxygen sensor signal voltage is compared to two calibratable thresholds in conjunction with certain activation and additional conditions.
The diagnosis shall also monitor if the lambda sensor gets ready in time.
Delayed upstream sensor readiness:
The diagnosis shall also monitor if the lambda sensor gets ready in time. after engine start.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
OC:
Internal resistance of upstream oxygen sensor (Released) > 60,000 Ohms
And
Duration in which lambda probe voltage lies within voltage band to detect fault ≥ 3 s
Fail Time > 200 ms Delayed upstream sensor readiness:
lambda sensor operative readiness not recognized after 35 s after dew point determination.
SECONDARY PARAMETERS AND ENABLE CONDITIONS
OC:
Enable Conditions:
Key "ON", Eng "ON"
HO2S heater = "ON"
0.376 V < Upstream oxygen sensor voltage < 0.474 V
The lambda controller shall be active.
Delay time for final diagnosis activation ≥ 10 s
This diagnostic is inhibited if any of the following DTC's are present:
O2 upstream sensor
Delayed upstream sensor readiness:
Enable Conditions:
Engine = ON, time for dew point in exhaust pipe exceeded
This diagnostic is inhibited if any of the following DTC's are present:
O2 upstream sensor error
TIME LENGTH AND FREQUENCY
Recurrence rate: 100 ms
HO2 sensor circuit low voltage
DTC
P0131 (B1S1) Refer to DTC P0131: HO2S Circuit Low Voltage Bank 1 Sensor 1. P0131
P0151 (B2S1) Refer to DTC P0151: HO2S Circuit Low Voltage Bank 2 Sensor 1. P0151
MONITOR STRATEGY DESCRIPTION
This Diagnostic detects a SCG in the circuit or the Oxygen Sensor.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Upstream oxygen sensor voltage < 0.024 V
And
Internal resistance of upstream oxygen sensor < 20 Ohms And
Downstream oxygen sensor voltage < 0.498 V
And
Limited value of lambda controller output >= Maximum of lambda control injection time correction factor
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Enable Conditions:
IGK "ON"
No CPS error
O2 sensor ready
MAF ≥ 8 kg/h
Time the lambda controller is active > 20 s
And
Valid conditions of resistance value of oxygen sensor upstream diagnosis short to ground are fulfilled
And
Mass air flow for diagnosis (after CPS closed) ≥ 30 g
And
lambda controller in limitation no lambda sensor error upstream and downstream
TIME LENGTH AND FREQUENCY
Recurrence rate: 100 ms
HO2 sensor circuit high voltage
DTC
P0132 (B1S1) Refer to DTC P0132: HO2S Circuit High Voltage Bank 1 Sensor 1. P0132
P0152 (B2S1) Refer to DTC P0152: HO2S Circuit High Voltage Bank 2 Sensor 1. P0152
MONITOR STRATEGY DESCRIPTION
Should a hard short to Vbatt exist on the oxygen sensor signal line, the signal voltage will tend to Vbatt and the analog digital converter value will tend to 5 V.
MALFUNCTION CRITERIA AND THRESHOLD VALUE(S)
Upstream Oxygen sensor voltage > 1,201 V
For fail time > 2,000 ms
SECONDARY PARAMETERS AND ENABLE CONDITIONS
Enable Conditions:
IGK "ON"
No O2 upstream sensor error
TIME LENGTH AND FREQUENCY
Recurrence rate: 100 ms
Mode $06 Data:
MODE $06 Data