Purge Control System Inspection

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

Connect the M-MDS to the DLC-2.
Start the engine and idle it.
Remove the plug hole plate. (See PLUG HOLE PLATE REMOVAL/INSTALLATION (VIN Y) .)
Disconnect the evaporative hose between the purge solenoid valve and the charcoal canister.
While idling the engine when cold, verify that vacuum is not applied by touching the purge solenoid valve with your finger as shown in the figure.

Courtesy of MAZDA MOTORS CORP.
- If vacuum is applied, inspect the following and repair or replace the malfunctioning location.
  - PCM PID: PRG_DUTY
    - Evaporative purge control signal (short to ground in wiring harness between purge solenoid valve terminal A and PCM terminal 1AW)
  - PCM output signal circuit (wiring harness, connector)
  - Purge solenoid valve (See AIRFLOW INSPECTION .)
Connect the evaporative hose.
When the 0% duty value of the purge solenoid valve is operated at a 100% duty value using the PCM simulation function [PRG_DUTY], verify that the PCM PID [SHRT_FUEL_TRIM] value fluctuates. (Refer to SIMULATION INSPECTION .) )
- If the PID [SHRT_FUEL_TRIM] value does not change, inspect the following.
  1. Switch the ignition OFF.
  2. Switch the ignition ON (engine off).
  3. When the 0% duty value of the purge solenoid valve is operated at a 50% duty value using the simulation function [PRG_DUTY], verify the operation sound of the purge solenoid valve. (Refer to SIMULATION INSPECTION .) )
- If the operation sound can be verified, inspect the following.
  - Evaporative hose disconnection or damage (between intake manifold and purge solenoid valve, and purge solenoid valve and charcoal canister)
- If the operation sound cannot be verified, inspect the following.
  - Purge solenoid valve (See AIRFLOW INSPECTION .)
  - Open circuit in wiring harnesses and connectors (between main relay terminal and purge solenoid valve terminal B, purge solenoid valve terminal A and PCM terminal 1AW)
WARNING:
- When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
- While performing this step, always operate the vehicle in a safe and lawful manner.
Drive the vehicle at an engine speed of approx. 2, 000 rpm for 30 s or more.
Verify that the PID [PRG_DUTY] value fluctuates between 0% and 100%.
- If the PID [PRG_DUTY] value fluctuation cannot be verified, replace the purge solenoid valve. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION (VIN Y) .)