EVAP Control System Monitor
OBD System Description - EVAP Control System MonitorEVPD Continuous Purge Flow
DTC Description / Detecting Condition / Confirmation Procedure
P0496 refer to DTC P0496: Evaporative (EVAP) Emission System Flow During Non-Purge. P0496
Monitor Strategy Description
Test is failed if tank vacuum exceeds prescribed threshold, based on fuel level, for a prescribed time.
Malfunction Criteria
Tank vacuum > Prescribed threshold, based on fuel level.
AND
Fail timer > 2 s
Enable Conditions
Ignition Voltage > 10 V
AND Ignition Voltage < 16 V
AND Barometric pressure > 72 kPa
AND Engine off time > 720 min.
OR (Startup IAT - Startup ECT < 12 degrees C
AND Startup ECT - Startup IAT) < 12 degrees C
AND Startup ECT > 0 degree C
AND Startup ECT < 40 degrees C
AND Startup IAT > 0 degree C
AND Startup IAT < 40 degrees C
AND Start-up IAT - IAT < 3 degrees C
AND Engine Run Time > 1 s
AND Engine Run Time < 100 s
Time required
Time Length and Frequency:
Test Runs once per key cycle.
EVPD Small Leak Test
DTC Description / Detecting Condition / Confirmation Procedure
P0442 refer to DTC P0442: Evaporative (EVAP) Emission System Small Leak Detected. P0442
Monitor Strategy Description
If a corrected vacuum decay slope and the individual segment slopes exceed their respective thresholds and the segment slopes are not convex then a small leak is present.
Malfunction Criteria
Decay slope, (beginning at decay start threshold 10 in. H2O
and lasting for decay time 10 s)
minus the larger vapor correction term,
(purge leak vapor term
OR Post decay vapor term)
greater than a threshold,
(the product of a base term > Refer to broken web link.
using fuel level
AND a temperature bias term) x Refer to broken web link.
AND
All 2 count
segment slopes greater than their threshold,
(the product of a base term > Refer to broken web link.
AND a temperature bias term x Refer to broken web link.
AND a segment bias term) x Refer to broken web link.
AND
The current segment slope minus the prior segment slope. Refer to broken web link. less than the convex threshold < 0.0996
Enable Conditions
Ignition Voltage > 10 V
AND Ignition Voltage < 16 V
AND Barometric pressure > 72 kPa
AND Engine off time > 720 min.
OR (Startup IAT - Startup ECT < 12 degrees C
AND Startup ECT - Startup IAT) < 12 degrees C
AND Startup ECT > 0 degree C
AND Startup ECT < 40 degrees C
AND Startup IAT > 0 degree C
AND Startup IAT < 40 degrees C
AND Start-up IAT - IAT < 3 degrees C
AND Engine Run Time > 1 s
AND Purge enable time < Refer to broken web link.
AND Cold test timer < 360 s
AND Fuel level > 0.06%
AND Fuel level < 0.93%
AND (Idle conditions met = TRUE
(Engine speed < 1,500 rpm
AND Vehicle speed < 3 kph
AND Throttle position) < 1.001%
OR Creep conditions met = FALSE
(Engine speed 1,500 rpm
AND Vehicle speed 6 kph
AND Throttle position) 1.9989%
AND Fuel not sloshing = FALSE
((Vehicle speed 2
OR Throttle position) 1.001
OR 125 ms MAP change 10
OR 125 ms Engine speed 100
AND 125 ms Fuel level delta) Refer to broken web link.
Time required
Time Length and Frequency:
Test Runs once per key cycle.
EVPD Large Leak Test
DTC Description / Detecting Condition / Confirmation Procedure
P0455 refer to DTC P0455: Evaporative (EVAP) Emission System Large Leak Detected. P0455
Monitor Strategy Description
Test is failed if tank vacuum cannot reach prescribed vacuum after a prescribed purge volume has been drawn from the tank.
Malfunction Criteria
At idle = TRUE
AND Tank vacuum < is less than threshold 10.0996 in. H2O
AND purge integral greater than threshold > Refer to broken web link.
OR
Not at idle = FALSE
AND Tank vacuum is less than threshold < 10.2002 in. H2O
AND purge integral greater than threshold > Refer to broken web link.
Enable Conditions
Ignition Voltage > 10 V
AND Ignition Voltage < 16 V
AND Barometric pressure > 72 kPa
AND Engine off time > 720 min.
OR (Startup IAT - Startup ECT < 12 degrees C
AND Startup ECT - Startup IAT) < 12 degrees C
AND Startup ECT > 0 degree C
AND Startup ECT < 40 degrees C
AND Startup IAT > 0 degree C
AND Startup IAT < 40 degrees C
AND Startup IAT - IAT < 3 degrees C
AND Purge enable time < Refer to broken web link.
AND Engine Run Time > 1 s
AND Cold test timer < 360 s
Time required
Time Length and Frequency:
Test Runs once per key cycle.
EVPD Very Small Leak Test
DTC Description / Detecting Condition / Confirmation Procedure
P0456 refer to DTC P0456: Evaporative (EVAP) Emission System Very Small Leak Detected. P0456
Monitor Strategy Description
If a corrected vacuum decay slope and the individual segment slopes exceed their respective thresholds and the segment slopes are not convex then a small leak is present.
Malfunction Criteria
Decay slope, (beginning at decay start threshold 10 in. H2O and lasting for decay time 360 s)
minus the larger vapor correction term,
(purge leak vapor term
OR Post decay vapor term)
greater than a threshold,
(the product of a base term > Refer to broken web link.
using fuel level
AND a temperature bias term) x Refer to broken web link.
AND
All 5 count
segment slopes greater than their threshold,
(the product of a base term > Refer to broken web link.
AND a temperature bias term x Refer to broken web link.
AND a segment bias term) x Refer to broken web link.
AND
The current segment slope minus the prior segment slope. Refer to broken web link. less than the convex threshold < 0.0195
Enable Conditions
Ignition Voltage > 10 V
AND Ignition Voltage < 16 V
AND Barometric pressure > 72 kPa
AND Engine off time > 720 min.
OR (Startup IAT - Startup ECT < 12 degrees C
AND Startup ECT - Startup IAT < 12 degrees C
AND Startup ECT > 0 degree C
AND Startup ECT < 40 degrees C
AND Startup IAT > 0 degree C
AND Startup IAT < 40 degrees C
AND Startup IAT - IAT < 3 degrees C
AND Engine Run Time > 1 s
AND Purge enable time < Refer to broken web link.
AND Cold test timer < 320 s
AND Fuel level > 0.06%
AND Fuel level < 0.93%
AND (Idle conditions met = TRUE
(Engine speed < 1,500 rpm
AND Vehicle speed < 3 kph
AND Throttle position) < 1.001%
OR Creep conditions met = FALSE
(Engine speed 1,500 rpm
AND Vehicle speed 6 kph
AND Throttle position)) 1.9989%
AND Fuel not sloshing = FALSE
((Vehicle speed 2
OR Throttle position) 1.001
OR 125 ms MAP change 10
OR 125 ms Engine speed) 100
AND 125 ms Fuel level delta) Refer to broken web link.
AND (Creep delay time
If Vehicle Speed > 2 kph
AND Creep Delay Timer/Decay Time) > 50%
Time required
Time Length and Frequency:
Test Runs once per key cycle.
EVPD Restricted Vent Path
DTC Description / Detecting Condition / Confirmation Procedure
P0446 refer to DTC P0446: Evaporative (EVAP) Emission Vent System Performance. P0446
Monitor Strategy Description
Test is failed if tank vacuum exceeds a prescribed threshold for a prescribed time when purging at a prescribed rate.
Malfunction Criteria
Tank vacuum greater than threshold > 8 in. H2O
for time
greater than threshold > 2 s
when purging at the prescribed rate 0.15 g/s
Enable Conditions
Ignition Voltage > 10 V
AND Ignition Voltage < 16 V
AND Barometric pressure > 72 kPa
AND Engine off time > 720 min.
OR (Startup IAT - Startup ECT < 12 degrees C
AND Startup ECT - Startup IAT) < 12 degrees C
AND Startup ECT > 0 degree C
AND Startup ECT < 40 degrees C
AND Startup IAT > 0 degree C
AND Startup IAT < 40 degrees C
AND Startup IAT - IAT < 3 degrees C
AND Engine Run Time > 1 s
AND Purge enable time < Refer to broken web link.
AND Cold test timer < 360 s
AND Fuel level > 0.06%
AND Fuel level < 0.93%
AND Restricted path test time < 220 s
Time required
Time Length and Frequency:
Test Runs once per key cycle.
Purge Solenoid Out Short Low/High
DTC Description / Detecting Condition / Confirmation Procedure
P0458 (Purge Solenoid Out Short Low) refer to DTC P0458: EVAP Control Circuit Low Voltage. P0458
P0459 (Purge Solenoid Out Short High) refer to DTC P0459: EVAP Solenoid Control Circuit High Voltage. P0459
Monitor Strategy Description
Detects a short to ground or open circuit on Purge Solenoid output circuit. The output driver hardware sets "Failure Criteria Met = TRUE" if output state does not equal the expected return voltage.
Malfunction Criteria
Fail Criteria Met = TRUE
Enable Conditions
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
Time Length and Frequency:
40 test failures within a 80 test samples.
Failure Time:
Continuous monitoring every 125 ms.
OUTD EGR Circuit Fault
DTC Description / Detecting Condition / Confirmation Procedure
P0403 refer to DTC P0403: Exhaust Gas Recirculation (EGR) Solenoid Control Circuit. P0403
Monitor Strategy Description
Detects a short to ground, battery or open circuit on EGR output circuit. The output driver hardware sets "Failure Criteria Met = TRUE" if output state does not equal the expected return voltage.
Malfunction Criteria
Fail Criteria Met = TRUE
Enable Conditions
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
Time Length and Frequency:
40 test failures within a 80 test samples.
Failure Time:
Continuous monitoring every 125 ms.
OUTD Vent Short Low/High
DTC Description / Detecting Condition / Confirmation Procedure
P0498 (OUTD Vent Short Low) refer to DTC P0498: EVAP Solenoid Control Circuit Low Voltage. P0498
P0499 (OUTD Vent Short High) refer to DTC P0499: EVAP Solenoid Control Circuit High Voltage. P0499
Monitor Strategy Description
Detects a short to ground or open circuit on Purge Solenoid output circuit. The output driver hardware sets "Failure Criteria Met = TRUE" if output state does not equal the expected return voltage.
Malfunction Criteria
Fail Criteria Met = TRUE
Enable Conditions
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
Time Length and Frequency:
40 test failures within a 80 test samples.
Failure Time:
Continuous monitoring every 125 ms.
Tank Pressure Stuck
DTC Description / Detecting Condition / Confirmation Procedure
P0451 refer to DTC P0451: Fuel Tank Pressure (FTP) Sensor Performance. P0451
Monitor Strategy Description
Continuously monitors the fuel tank pressure sensor output for a stuck condition.
Malfunction Criteria
Transition Monitor Logic (Normal purge to purge OFF):
Delta Tank Vacuum < 0.9995%
for
Time Period > 10
Evaporative Emissions Diagnostic Mode Logic:
Vacuum Intergral (signed) > Refer to broken web link.
modified by
multiplier 0.95
for
Time Period > 10
Enable Conditions
Enable conditions for Purge Transition test:
= 0 enum
(Normal purge to Purge off) > 0.3501 g/s
Evaporative system active flag = 0 enum
Purge flow > 0.3501 g/s
OR
Enable Conditions during EVAP Diagnostic test:
Evaporative diagnostic status = 2 or 3 enum
(2 = EVAP Diag Control)
(3= Closed Loop Purge)
Time required
Time Length and Frequency:
Transition Monitor Logic (Normal purge to purge OFF):
Runs during transition from normal purge to purge OFF.
Evaporative Emissions Diagnostic Mode Logic:
Can run once per key cycle.
Tank Pressure Short Low
DTC Description / Detecting Condition / Confirmation Procedure
P0452 refer to DTC P0452: Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage. P0452
Monitor Strategy Description
Detects sensor signal short to low voltage.
Malfunction Criteria
Raw Tank Pressure < 0.017%
Enable Conditions
IF Ignition ON = ON
SET Enable Criteria Met Flag to TRUE = TRUE
Time required
Time Length and Frequency:
100 test failures within a 200 test samples.
Failure Time:
Continuous monitoring every 125 ms.
Tank Pressure Short High
DTC Description / Detecting Condition / Confirmation Procedure
P0453 refer to DTC P0453: Fuel Tank Pressure (FTP) Sensor Circuit High Voltage. P0453
Monitor Strategy Description
Detects sensor signal short to high voltage.
Malfunction Criteria
Raw Tank Pressure > 0.983%
Enable Conditions
IF Ignition ON = ON
SET Enable Criteria Met Flag to TRUE = TRUE
Time required
Time Length and Frequency:
100 test failures within a 200 test samples.
Failure Time:
Continuous monitoring every 125 ms.
Tank Pressure Noisy Signal
DTC Description / Detecting Condition / Confirmation Procedure
P0454 refer to DTC P0454: Fuel Tank Pressure (FTP) Sensor Circuit Intermittent. P0454
Monitor Strategy Description
The Tank Pressure Noisy Diagnostic continuously monitors the fuel tank pressure to determine if there is external noise impinging on the fuel tank pressure measurement.
Malfunction Criteria
Delta Tank Pressure > Limit? > 12.5
Enable Conditions
IF Engine Running = RUN
AND Intake Air Temperature >= 0 degree C
AND Fuel Tank Vacuum Offset Update Complete? = TRUE
AND Diag Tank Pressure Short Fault Present? = FALSE
OR Noisy Signal Disabling Faults Present = FALSE
Time required
Time Length and Frequency:
12 test failures within a 80 test samples.
Failure Time:
Continuous monitoring every 125 ms.
Fuel Level Consumption (Stuck)
DTC Description / Detecting Condition / Confirmation Procedure
P0461 refer to DTC P0461: Fuel Level Sensor Performance. P0461
Monitor Strategy Description
Detects a stuck fuel level sender.
Malfunction Criteria
Fuel Level Change <= 0.035
AND
Present Odometer - Previous Odometer >= 250
Enable Conditions
IF Engine Running = RUN
AND Fuel Level Fault Present = FALSE
Time required
Time Length and Frequency:
Dependent on drive conditions.
Fuel Level Short Low
DTC Description / Detecting Condition / Confirmation Procedure
P0462 refer to DTC P0462: Fuel Level Sensor Circuit Low Voltage. P0462
Monitor Strategy Description
Detects a continuous short to low or open in either the signal circuit or the fuel level sender.
Malfunction Criteria
Raw fuel level sender output < 0.05%
Enable Conditions
IF Engine Running = RUN
Set Short diagnostic Enable Criteria Met Flag = TRUE
Time required
Time Length and Frequency:
80 test failures within a 160 test samples.
Failure Time:
Continuous monitoring every 125 ms.
Fuel Level Short High
DTC Description / Detecting Condition / Confirmation Procedure
P0463 refer to DTC P0463: Fuel Level Sensor Circuit High Voltage. P0463
Monitor Strategy Description
Detects a continuous short to battery in either the signal circuit or the fuel level sender.
Malfunction Criteria
Raw fuel level sender output > 0.85%
Enable Conditions
IF Engine Running = RUN
Set Short diagnostic Enable Criteria Met Flag = TRUE
Time required
Time Length and Frequency:
80 test failures within a 160 test samples.
Failure Time:
Continuous monitoring every 125 ms.
Fuel Level Noisy Signal
DTC Description / Detecting Condition / Confirmation Procedure
P0464 refer to DTC P0464: Fuel Level Sensor Circuit Intermittent. P0464
Malfunction Criteria
Difference between previous and current Fuel Level Raw Signal > 0.0392
Enable Conditions
Determination of Steady Conditions
IF Engine Running = RUN
Delta MAP =< 10 kPa
AND Delay Timer >= 5 s
THEN Set Delta MAP Condition Not Exceeded Flag to TRUE = TRUE
OR
Delta RPM =< 50 rpm
AND Delay Timer >= 5 s
THEN Set Delta RPM Condition Not Exceeded Flag to TRUE = TRUE
OR
Throttle Position =< 1.9989%
AND Delay Timer >= 5 s
THEN Set TPS Condition Not Exceeded Flag to TRUE = TRUE
OR
Vehicle Speed >= 1 kph
AND For Delay Timer of >= 5 s
THEN Set V. Speed Condition Not Exceeded Flag to TRUE = TRUE
Determination of Noisy Signal Enable Condition
IF Engine Running = RUN
AND Intake Air temperature >= -10
AND Fuel Level Active Fault Present = FALSE
AND Noisy Signal Disabling Faults Present? = FALSE
AND Delta MAP Condition Exceeded = FALSE
AND Delta RPM Condition Exceeded = FALSE
AND TPS Condition Exceeded = FALSE
AND Vehicle Speed Condition Exceeded = FALSE
THEN Set Enable Criteria Met Conditions are Satisfied = TRUE
Time required
Time Length and Frequency:
50 test failures within a 80 test samples.
Failure Time:
Continuous monitoring every 125 ms.
Table A
MODE $06 Data:
MODE $06 Data