DTC Advanced Diagnostics: P145D
DTC P145D:Evaporative Emission (EVAP) System Purge Flow Malfunction at turbocharging

General Description


Negative side purge flow
Boost side purge flow
Purge back-flow (P2450)
Condition
Flowing
Flowing
OK
Purge line normal, EVAP canister purge valve normal
Flowing
Flowing
NG (P2450)
Non-return valve A abnormal
Not flowing
Flowing
–
Negative side purge line abnormal
Flowing
Not flowing
–
Boost side purge line abnormal
Not flowing
Not flowing
–
Purge line abnormal, EVAP canister purge valve open

The fuel vapor in the fuel tank is temporarily stored in the evaporative emission (EVAP) canister and drawn into the engine through the EVAP canister purge valve. The powertrain control module (PCM) controls the amount of vapor introduced into the engine by varying the duty cycle of the EVAP canister purge valve according to the condition of the engine.

The PCM checks the purge flow conditions on both negative and boost pressure sides. If either side of the purge flow is detected as abnormal, it is determined that there is a clog or disconnection on the abnormal side of the purge line. If both sides of the purge flow are detected as abnormal, it is determined that the purge lines are abnormal or the EVAP canister purge valve is stuck opened.

Purge flow check of boost pressure side:

The EVAP canister purge valve opens normally (EVAP canister purge valve OPEN OK) and detects that the purge flow is normal when the pulse of the EVAP canister purge valve duty cycle is transmitted to the fuel tank pressure (FTP) sensor during purge flow (pulse method).

OK determination: Pulse exists (P145D OK)
P04F0 Purge flow OK
P04DF EVAP canister purge valve stuck Open OK

NG determination: No pulse (P145D NG)
Either purge flow P04F0 abnormality or P04DF EVAP canister purge valve OPEN failure
In this case, if purge flow check of negative pressure side P0441 is determined as OK or P04DF is determined as OK by the check after the vehicle condition is turned to the OFF (LOCK) mode after P0441 is determined as NG, the purge flow check of boost pressure side P04F0 is determined as NG

When P04DF is determined as OK after the vehicle condition is turned to the OFF (LOCK) mode, P04F0 is also determined after the vehicle condition is turned to the OFF (LOCK) mode.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Once per driving cycle
Sequence
None
Duration
11 seconds*1 (9.5 seconds)*2 or more
DTC Type
Two drive cycles, MIL on
*1: L15B7 (except Si) and L15BY
*2: L15BA

Enable Conditions
Condition
Minimum
Maximum
Engine coolant temperature [ECT SENSOR 1] before EVAP purge control starts
131 °F (55 °C)
–
MAP value [MAP SENSOR]
115 kPa (860 mmHg, 33.9 inHg)
–
Boost pressure
14 kPa (100 mmHg, 4 inHg)
–
12 volt battery voltage [BATTERY]
10.5 V
–
Fuel trim
0.75
1.47
EVAP canister purge valve duty [EVAP PC DUTY]
30 %
80 %
Fuel feedback
Closed loop at stoichiometric
[ ]: HDS Parameter

Malfunction Threshold
The pulses detected by the FTP sensor are 30 % or less for at least 11 seconds*1 (9.5 seconds)*2.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
EVAP canister purge valve closed stuck
EVAP canister purge valve open stuck
FTP sensor stuck
EVAP system line clogged
EVAP system line misinstalled

Confirmation Procedure
Operating Condition
1.
Start the engine. Hold the engine speed [ENGINE SPEED] at 3,000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on.
2.
Let the engine idle for at least 64 seconds.
3.
Drive the vehicle at high load for total of at least 11 seconds.
4.
Turn the vehicle to the OFF (LOCK) mode and leave the vehicle for at least 10 seconds.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.