Emissions - OBD EGR DTC Confirmation Procedure

FORENZA

Section Title: Engine
TSB No. TS 26 10200

Division: Automotive
Category: Technical

SUBJECT:
ON-BOARD DIAGNOSTIC (OBD) SYSTEM DTC CONFIRMATION

PROCEDURE: EGR (EXHAUST GAS RECIRCULATION)

MODEL(S):
FORENZA, FORENZA WAGON, RENO (RQ420)

YEAR:
2004~2008

CONDITION:
Diagnostic readiness status is "Incomplete".

CAUSE:
Requirements have not been met under the specific vehicle conditions and procedures.

CORRECTION:
Please follow the attached DTC Confirmation Procedures outlining what is required for the readiness status to complete.

The conditions and procedures are exclusive to the model(s) listed above, and apply only to setting the readiness status of the EGR (Exhaust Gas Recirculation) to the "YES" condition.

Note:
The following specifications and procedures do not relate to any specific repair or failure state, they represent the minimum requirements that the system must experience during the self diagnostic sequence for this specific component.

EGR (Exhaust Gas Recirculation)

Description

The purpose of this procedure is to satisfy the enable criteria necessary in order to execute the EGR System diagnostic. Ensure the vehicle meets the requirements listed in Conditions for Running before performing this test. Failure to meet the necessary requirements may produce inaccurate test results.

Conditions for Running

Check to make sure that following conditions are satisfied when using this DTC CONFIRMATION

PROCEDURE:

> Atmospheric pressure : higher than 540 mmHg (Altitude : lower than 2,790 m (9,150 ft))

> Ignition voltage is between 11 and 16 volts

> Coolant temp. > 75°C (167°F)

> Intake Air temp. > 5°C (41 °F)

Diagnostic Aids

> The readiness status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the readiness status will update to YES. If a test for a specific system has failed, the readiness status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the scan tool will output the DTC and malfunction indicator lamp (MIL) status.

> The first failure of a type B DTC does not constitute a final determination of pass or fail, and will not update the readiness status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down. The readiness status will update only when the DTC fails the second time, or when all of the tests pass. If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list, and review the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in the engine load, such as a cooling fan or an A/C compressor clutch turning on, may cause the test to abort.

> If a diagnostic test is difficult to run, observe the scan tool display while maintaining the necessary enable conditions until the readiness status updates to YES.

Step Action (Detecting Condition)

1. Connect scan tool to DLC with ignition switch OFF

2. Start engine.

3. Drive vehicle on a level road at a steady throttle position at 55 to 65 mph for 30 seconds.

4. Return pedal to idle position and allow vehicle to decelerate to 25 mph. (Do not brake).

5. Repeat Steps 3 and 4 three times.

6. Check DTC by using scan tool.