For California

DTC P1421 COLD START CONTROL





Description
ECM controls ignition timing and engine idle speed when engine is started with prewarming up condition.
This control promotes the activation of three way catalyst by heating the catalyst and reduces emissions.




On Board Diagnosis Logic









DTC Confirmation Procedure

NOTE:
- If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
- If DTC P1421 is displayed with other DTC, first perform the trouble diagnosis for other DTC.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.

WITH CONSULT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select "DATA MONITOR" mode with CONSULT-III.
4. Check that the "COOLAN TEMP/S" indication is between 5�C (41�F) and 36�C (97�F).
If "COOLAN TEMP/S" indication is within the specified value, go to the following step.
If "COOLAN TEMP/S" indication is out of the specified value, cool engine down or warm engine up and go to step 1.
5. Start engine and let it idle for 5 minutes.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to For California.

WITH GST
Follow the procedure "WITH CONSULT-III" above.




Diagnosis Procedure
1.PERFORM IDLE AIR VOLUME LEARNING
Perform For California.
Is Idle Air Volume Learning carried out successfully?
Yes or No
Yes - GO TO 2.
No - Follow the instruction of Idle Air Volume Learning.
2.CHECK INTAKE SYSTEM
Check for the cause of intake air volume lacking. Refer to the following.
- Crushed intake air passage
- Intake air passage clogging
OK or NG
OK - GO TO 3.
NG - Repair or replace malfunctioning part
3.CHECK FUEL INJECTION SYSTEM FUNCTION
Perform For California for DTC P0171.
OK or NG
OK - GO TO 4.
NG - Go to For California for DTC P0171.
4.PERFORM DTC CONFIRMATION PROCEDURE
1. Erase DTC.
2. Perform DTC Confirmation Procedure.
See For California.
3. Is the 1st trip DTC P1421 displayed again?
Yes or No
Yes - GO TO 5.
No - INSPECTION END
5.REPLACE ECM
1. Replace ECM.
2. Perform initialization of NVIS (NATS) system and registration of all NVIS (NATS) ignition key IDs. Programming and Relearning.
3. Perform For California.
4. Perform For California.
5. Perform For California.
6. Perform For California.
- INSPECTION END