• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition Voltage | P0499 00 | P0498 00 | -- | -- |
EVAP Canister Vent Solenoid Valve Control Circuit | P0498 00 | -- | P0499 00 | -- |
The evaporative emission (EVAP) canister vent valve is used for EVAP system diagnostics. The EVAP canister vent solenoid valve is a normally open valve. Battery positive voltage is supplied directly to the EVAP canister vent solenoid valve. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage. If the ECM detects the control circuit voltage is within a predetermined range when the circuit is commanded OFF, this DTC sets.
• | The engine speed is greater than 80 RPM. |
• | The ignition voltage is between 10-18 V. |
• | The ECM has commanded the EVAP canister vent solenoid valve ON and OFF at least once during the ignition cycle. |
• | DTCs P0498 00 or P0499 00 run continuously once the above conditions are met. |
The ECM detects the voltage on the EVAP canister vent solenoid valve control circuit is less than 2.6 V when the driver is commanded OFF. The condition is present for greater than 4 s or for a cumulative of 30 s.
The ECM detects the voltage on the EVAP canister vent solenoid valve control circuit is greater than 4.6 V when the driver is commanded ON. The condition is present for greater than 4 s or for a cumulative of 30 s.
• | DTC P0498 00 and P0499 00 are Type B DTCs. |
• | The EVAP system will only purge during open loop. |
DTC P0498 00 and P0499 00 are Type B DTCs.
Evaporative Emission Control System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the Q13 Evaporative Emission (EVAP) Canister Vent Solenoid Valve. |
⇒ | If less than the specified range, repair the short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM). |
Note: The control circuit for the EVAP vent solenoid valve is pulled-up to voltage within the K20 Engine Control Module (ECM), 2.6-4.6 V on the control circuit is normal.
⇒ | If more than the specified range, repair the short to B+. If the circuit tests normal, replace the K20 Engine Control Module (ECM). |
⇒ | If more than the specified range, repair the open circuit. If the circuit tests normal, replace the K20 Engine Control Module (ECM). |
⇒ | If not within the specified range, replace the Q13 Evaporative Emission (EVAP) Canister Vent Solenoid Valve. |
⇒ | If not within the specified value, replace the Q13 Evaporative Emission (EVAP) Canister Vent Solenoid Valve. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | LINK (Evaporative Emission Canister Vent Solenoid Valve Replacement) |
• | Control Module References for ECM replacement, setup, and programming |