Diagnostic Aids

WARNING: This page is about a different variant/trim than selected.

A diagnosed EVAP canister purge solenoid valve or EVAP canister vent solenoid valve circuit fault may have caused this DTC to set.
The ECM uses the FTP sensor to detect the amount of vacuum pulled on the EVAP system during the leak diagnostic tests. Ensure that the fuel pressure sensor is not skewed by verifying the FTP sensor on the scan tool is between 1.30-1.70 volts with the ignition ON and the fuel cap removed.
The most likely cause of DTC P0496 is a stuck open EVAP canister purge solenoid valve. Command the EVAP canister purge solenoid valve ON, PWM, with the scan tool. The valve should click at an even rate. Replace the solenoid if the solenoid intermittently sticks.
A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for vacuum decay, this type of leak may be detected.

DTC P0496

Step	Action	Values	Yes	No
Schematic Reference: Evaporative Emissions (EVAP) Hose Routing Diagram and Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Disconnect the evaporative emission (EVAP) canister side of the purge pipe from the EVAP purge solenoid. Install a hand held vacuum gage to the EVAP canister purge solenoid valve purge port. Disconnect the EVAP canister purge solenoid valve harness connector. Monitor vacuum on the vacuum gage. Start the engine and allow the engine to idle. Increase the idle to 1,200-1,500 RPM. Does the vacuum gage indicate an increase in vacuum?	-	Go to Step 8	Go to Step 3
3	Connect the EVAP canister purge solenoid valve harness connector. Monitor vacuum on the vacuum gage. Increase the idle to 1,200-1,500 RPM. Does the vacuum gage indicate an increase in vacuum?	-	Go to Step 5	Go to Step 4
4	Turn OFF the ignition. Remove and then install the fuel fill cap. Turn ON the ignition, with the engine OFF. Observe the Fuel Tank Pressure Sensor parameter with a scan tool. Is the Fuel Tank Pressure Sensor parameter within the specified value?	1.30-1.70 V	Go to Diagnostic Aids	Go to Step 7
5	Test the EVAP canister purge solenoid valve control circuit for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs . Did you find and correct the conditions?	-	Go to Step 9	Go to Step 6
6	Test for an intermittent and for a poor connection at the EVAP canister purge solenoid valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 9	Go to Step 8
7	Replace the fuel tank pressure (FTP) sensor. Refer to Fuel Tank Pressure Sensor Replacement . Did you complete the replacement?	-	Go to Step 9	-
8	Replace the EVAP canister purge solenoid valve. Refer to Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement . Did you complete the replacement?	-	Go to Step 9	-
9	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	-	Go to Step 2	Go to Step 10
10	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List - Vehicle	System OK