Evaporative System Test

Evaporative system test outline
- To verify that the problem has been fixed properly after repairs, the run Drive Cycle or evaporative system test must be performed.
- The evaporative system test, which can substituted for the run Drive Cycle as an EVAP control system repair confirmation method, can be done while operating the WDS at idle instead of actually driving the vehicle.

Evaporative system test description







- The evaporative system test finds gas leaks in the system using the PCM to monitor changes in the EVAP system leak detection pump air pump load current. This test starts after sending an on-demand test signal from the WDS to the PCM. The PCM controls the Air pump and Change over valve (COV) operation and also stores the load current of the air pump as follows:
- The PCM commands turn the air pump on and retrieve the air pump load current value (LDP_MON PID) as a reference current (LDP_REF PID).
- After retrieving a reference current value, the PCM commands the Change over valve (COV) to open, then captures the air pump load current value (LDP_MON PID) as idle current (LDP_IDL PID). The evaporative system will be pressurized from the phase.
- The PCM continues to monitor the air pump load current value (LDP_MON PID) until the end of the test.

- You can confirm whether any evaporative gas leak occurred or not by reading the test results.

Evaporative system malfunction determination
- The WDS calculates the stored air pump load current value and displays the results as follows:
- Small leak results (DTC P0442): LDP_SLDV
- very small leak results (mA/s: DTC P0456): LDP_VSLDV
- very small leak results (mA: DTC P0456): LDP_REF-LDP_MON (when test ended)
- IMO results (Air pump operation): LDP_MON (when test ended)
- COV results (Change over valve statues): LDP_REF-LDP_IDL

Evaporative system test procedure
1. Select the EVAP test from the Toolbox on the WDS display and follow its instructions.

Specification:

2. Verify all of the following PIDs are within the specifications at pre-test confirmation screen.
3. Start the engine and run it at 3,500 rpm for 200 sec. to warm it up completely.
4. Press tick icon to start the test.




5. Verify that each result is within the specifications in the table, using the FTL_V PID recorded in Step 2.
- If WDS values are out of range, diagnosis the problem using the DTC troubleshooting procedure or component inspection procedure.

Evaporative system test threshold value




Small leak




Very small leak (mA/s)

Very small leak (mA)
- If LDP_MON PID value (when test ended) is lower than the LDP_REF PID value, a very small leak has been detected.

IMO (Air pump operation)
- If LDP_MON PID value stay 0 V during the test, EVAP system leak detection pump circuit has electrical malfunction.

COV (Change over valve statues)
- If LDP_REF-LDP_IDL PID value is lower than 0.002 A, Change over valve (COV) is stuck closed.