Catalyst Monitor
OBD System Description - Catalyst MonitorCatalyst Bank1
DTC Description / Detecting Condition / Confirmation Procedure
P0420 refer to P0420
Monitor Strategy Description
Detects reduced Catalyst conversion efficiency, through correlation of Oxygen Storage. A/F shifts are commanded at idle, and Oxygen Sensors are monitored to determine the amount of Oxygen Storage (in units of time), which is EWMA filtered.
Malfunction Criteria
EWMA Oxygen Storage Time for Bank 1 (to report FAIL) <= 2.25 s (when passing) To Pass this Monitor After a Failure is Detected, the Following Must be Met: EWMA Oxygen Storage Time for Bank 1 (to report PASS) >= 2.75 s (when failing) - allows hysteresis to prevent excessive MIL cycling
Enable Conditions
Engine Runtime Sufficient >= 570 s
AND (Purge Concentration Learned = TRUE
OR Low Purge Fuel Concentration) = TRUE
AND Airflow within range: <= 8.5 g/s (For AT)
AND Airflow within range: <= 7.5 g/s (For MT)
>= 2.25 g/s
AND Throttle closed <= 1.5015%
AND Coolant Temp within range >= 70 °C
<= 109 °C
AND Ambient Temp within range >= -7 °C
<= 105 °C
AND Barometric Pressure above minimum >= 72 kPa
AND Number of Test Attempts Not Excessive <= 12
AND Closed Loop enabled = TRUE
AND Torque Fuel Reduction not active (Torque Control) = FALSE
AND Catalyst Temp within range <= 975 °C
>= 300 °C
AND Fuel Integrator deviation from stoich below maximum <= 0.03
AND Vehicle speed below maximum <= 3 kph
AND (A/T PN Transitions Not Allowed = 0
AND (Auto Trans not in P/N)) = TRUE
OR (A/T PN Transitions Allowed = 0
AND (P/N transitions period below max. allowed)) <= 1.5
AND BLM Learn completed = TRUE
AND (Sufficient Driving Airflow (since last test) >= 11 g/s (For AT)
AND (Sufficient Driving Airflow (since last test) >= 9 g/s (For MT)
present for Sufficient Time to Prep Catalyst) >= 12 s
AND End of Diagnostic Airfuel Ramping = FALSE
AND Not idling for too long <= 75 s
AND Test not complete (Sampling Allowed) = FALSE
AND No disabling faults present = FALSE
AND No instrumentation slews active = FALSE
AND No OFVC device control active = FALSE
Time required
Diagnostic runs during extended idle
MODE $06 Data
VIM_1_OutputFault
DTC Description / Detecting Condition / Confirmation Procedure
P0660 refer to P0660.
Monitor Strategy Description
Detects a short to ground, to battery or open circuit on VGIS 1 output. Fault information provided by an output driver chip.
Malfunction Criteria
Output driver IC internal feedback voltage less than state calls for high voltage = TRUE OR output driver IC internal feedback voltage greater than state calls for low voltage = TRUE
Enable Conditions
No disabling Faults Present = FALSE
AND Engine Running = RUN
AND Ignition Voltage >= 11 V
AND Ignition Voltage <= 16 V
AND Enable Time delay >= 0.5 s
Time required
Detection Time
5.00 seconds failure out of 9.88 seconds sample period
Continuous Monitoring every 125.00 ms
Detection Samples
40 test failures within 80 test samples at 125. ms loop time
Variable Geometry Intake System Circuit Low
DTC Description / Detecting Condition / Confirmation Procedure
P2077 refer to P2077.
Monitor Strategy Description
This code detects a short to ground in either the circuit or the sensor.
Malfunction Criteria
VGIS sensor signal < 4.9988%
Enable Conditions
Engine Runtime > 5 sec.
Time required
Detection Time
12.50 seconds failure out of 24.88 seconds sample period
Continuous Monitoring every 125.00 ms
Detection Samples
100 test failures within 200 test samples at 125. ms loop time
Variable Geometry Intake System Circuit High
DTC Description / Detecting Condition / Confirmation Procedure
P2078 refer to P2078.
Monitor Strategy Description
This code detects a continuous short to high or open circuit in either the circuit or the sensor (5-95%).
Malfunction Criteria
VGIS sensor signal > 94.9996%
Enable Conditions
Engine Runtime > 5 sec.
Time required
Detection Time
12.50 seconds failure out of 24.88 seconds sample period
Continuous Monitoring every 125.00 ms
Detection Samples
100 test failures within 200 test samples at 125. ms loop time
Variable Geometry Intake System Performance
DTC Description / Detecting Condition / Confirmation Procedure
P2076 refer to P2076.
Monitor Strategy Description
This code detects a sensor that is not in the desired position.
Malfunction Criteria
Actual VGIS State = Desired VGIS State n/a
Enable Conditions
No disabling Faults Present = FALSE boolean
AND Previous VGIS circuit Fail high = FALSE boolean
AND Previous VGIS circuit Fail Low = FALSE boolean
AND Engine Runtime > 1 sec.
AND IAT > -30 °C (For AT)
AND IAT > 15 °C (For MT)
AND Current VGIS Position state = Previous VGIS state boolean
AND Manifold Absolute Vacuum < 15 kPa (For AT)
AND Manifold Absolute Vacuum < 30 kPa (For MT)
AND Low Vacuum Timer < 10 sec. (For AT)
AND Low Vacuum Timer < 6 sec. (For MT)
AND VGIS Enable Timer > 1 sec.
Time required
Detection Time
10.00 seconds failure out of 19.88 seconds sample period
Continuous Monitoring every 125.00 ms
Detection Samples
80 test failures within 100 test samples at 125. ms loop time