DTC P0497

DTC P0497: Evaporative Emission (EVAP) System Low Purge Flow Detected

General Description

Courtesy of HONDA, U.S.A., INC.

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 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 (P145C*1 (P0441)*2 OK)

P0497 Purge flow OK
P0496 EVAP canister purge valve stuck Open OK

NG determination: No pulse (P145C*1 (P0441)*2 NG)

Either purge flow P0497 abnormality or P0496 EVAP canister purge valve OPEN failure.
In this case, classify the failed part according to <STEP 2>.

If there is no pulse, it is determined as either no purge flow or the EVAP canister purge valve is stuck OPEN:

When the FTP sensor fluctuates from negative pressure to atmospheric pressure after the vehicle condition is turned to the OFF (LOCK) mode: P0496 EVAP canister purge valve stuck OPEN

When there is no fluctuation of the FTP sensor: P0497 purge flow NG

*1: 2014 - 2015 models

*2: 2016 model on and after

Monitor Execution, Sequence, Duration, DTC Type, OBD Status

Execution	Once per driving cycle
Sequence	P145C1 (P0441)2 is judged as NG
Duration	-
DTC Type	Two drive cycles, MIL on
OBD Status	PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions

Condition	Minimum	Maximum
Low load duration time	10 seconds	-
Wait for stability after the vehicle condition is turned to the OFF (LOCK) mode	10 seconds	-
Engine coolant temperature [ECT SENSOR 1] before EVAP purge control starts	140 deg.F (60 deg.C)	-
No active DTCs set (prevents monitor from running)*1	P0087, P0088, P0101, P0102, P0103, P0107, P0108, P0117, P0118, P0134, P0135, P0154, P0155, P0192, P0193, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0335, P0339, P0351, P0352, P0353, P0354, P0355, P0356, P0443, P0451, P0452, P0453, P0496, P0498, P0499, P064A, P0685, P1109, P1128, P1129, P1172, P1174, P1454, P2195, P2197, P2227, P2228, P2229, P2237, P2238, P2240, P2241, P2243, P2245, P2247, P2249, P2251, P2252, P2254, P2255, P2279, P2422, P2652, P2654
No active DTCs set (prevents monitor from running)*2	P0069, P0087, P0088, P0101, P0102, P0103, P0107, P0108, P0117, P0118, P0134, P0135, P0154, P0155, P0192, P0193, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0335, P0339, P0351, P0352, P0353, P0354, P0355, P0356, P0443, P0451, P0452, P0453, P0496, P0498, P0499, P064A, P0685, P1109, P1172, P1174, P1454, P2073, P2074, P2195, P2197, P2228, P2229, P2237, P2238, P2240, P2241, P2243, P2245, P2247, P2249, P2251, P2252, P2254, P2255, P2279, P2422, P2652, P2654

[ ]: HDS parameter

Malfunction Threshold

The output from the FTP sensor [FTP SENSOR] is less than 0.2 kPa (0.07 inHg, 2 mmHg) for at least 10 seconds.

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
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 3000 RPM without load (in P or N) until the radiator fan comes on.
2.
Let the engine idle for at least 64 seconds.
3.
Turn the vehicle to the OFF (LOCK) mode and leave the vehicle for at least 10 seconds.

With the HDS

Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

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 battery.