Diagnostic Routine

DIAGNOSTIC ROUTINE

Procedure

Order

Basic Diagnostic Procedures

1st

Entering Diagnostics

2nd

Retrieving Trouble Codes

3rd

Symptoms ⁽¹⁾

4th

Intermittents ⁽¹⁾

5th

⁽¹⁾	Symptoms and intermittents are covered in TESTS W/O CODES article.

NOTE: For additional information on self-diagnostic system, see THEORY/OPERATION article.

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed with ENTERING SELF-DIAGNOSTICS in this article. If no fault codes or only pass codes are present, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).

The self-diagnostic system is used for diagnosing malfunctions of major sensors and actuators of the Electronic Concentrated Control System (ECCS). The Electronic Control Unit (ECU) has 5 available diagnostic modes within the computer. Before selecting any mode of self-diagnosis, always perform BASIC TESTING first. This will eliminate wasted diagnostic time and invalid diagnostic results.

NOTE: When performing BASIC TESTING , be careful not to erase any diagnostic information stored in the ECU memory.