Engine Controls - MIL ON/DTC P0420 Stored

08-002

October 11, 2011

Applies To:
2005-06 Element - All Models With M/T

2005-06 Element: MIL Comes On With DTC P0420
(Supersedes 08-002, dated July 21, 2011, to revise the information marked by asterisks and black bars.)

REVISION SUMMARY

* Under WARRANTY CLAIM INFORMATION, the flat rate time was changed.*

SYMPTOM

The MIL is on, and DTC P0420 (catalyst system efficiency below threshold) is stored.

PROBABLE CAUSE

The ECM software misinterprets sensor inputs as a deteriorated catalytic converter.

CORRECTIVE ACTION

Update the ECM software, and check the three-way catalytic converter.

WARRANTY CLAIM INFORMATION





The normal warranty applies.

Failed Part: P/N 37820-PZD-A11

Defect Code: 03214

Symptom Code: 03203

Skill Level: Repair Technician

SOFTWARE VERSION

HDS Software Version: 2.012.013 (December 2007) or later.

Database Update: 27-Nov-2007 or later.

NOTE:
An incorrect HDS software version may indicate that the vehicle does not need an update.





The updated PGM-FI software program ID and P/N is shown. If this, or a later program ID, is the Current Program ID displayed during the update, the software for this service bulletin is already installed.

REPAIR PROCEDURE

1. Update the ECM with the HDS and software version 2.012.013 or later. Refer to Service Bulletin 01-023, Updating Control Units/Modules.

2. Clear the DIG with the HDS, and leave the HDS connected.

3. Start the engine. Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle. Verify that the ECT sensor is above 158°F (70°C).

4. Test-drive the vehicle in 5th gear, between 45 and 75 mph, for at least 5 minutes, with the cruise control set, to warm up the three-way catalytic converter.

Then test the three-way catalytic converter by maintaining a vehicle speed of 25 mph or more, for at least 5 minutes, with the cruise control set.

NOTE:
The optimal speed to test the catalytic converter is 55 mph.

5. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS while driving.

Does the screen indicate PASSED?

Yes - The vehicle is OK at this time.

No - If the screen indicates EXECUTING, keep driving until a result appears. If the screen indicates OUT OF CONDITION, go to step 4. If the screen indicates FAILED, replace the three-way catalytic converter.

NOTE:
In most cases, DTC P0420 is caused by the ECM software. In rare cases, the three-way catalytic converter needs to be replaced.





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