Diagnostic Procedure
Refer to ENTERING ON-BOARD DIAGNOSTICS to retrieve fault codes. If fault codes are NOT present and/or DRB-II (Diagnostic Readout Box-II) is used, proceed to one of the following tests:
- Go to NO START TEST 1A (NS-1A) chart if a no-start condition exists or engine stalls after start-up. Perform indicated VERIFICATION PROCEDURE chart after repairs. Ensure charts apply to engine being tested.
- Go to DRIVEABILITY TEST 1A (DR-1A) chart if engine runs but has performance problems. Perform indicated VERIFICATION PROCEDURE chart after repairs. Ensure charts apply to engine being tested.
NOTE:
When using trouble shooting charts for diagnosis, DO NOT
skip any steps in chart or incorrect diagnosis may result.
Before proceeding with diagnosis, the following precautions must be followed:
- Vehicle must have a fully charged battery and functional charging system.
- Probe SBEC connector from pin side. DO NOT backprobe SBEC connector.
- DO NOT cause short circuits when performing electrical tests. This will set additional fault codes, making diagnosis of original problem more difficult.
- DO NOT use a test light in place of a voltmeter.
- When checking for spark, ensure coil wire is NO more than 1/4" from ground. If coil wire is more than 1/4" from ground, damage to vehicle electronics and/or SBEC may result.
- DO NOT prolong testing of fuel injectors or engine may hydrostatically (liquid) lock.
- Always repair lowest fault code number (CHECK ENGINE light) or first fault displayed (DRB-II) first.
- Always perform verification procedure test after repairs are made.
- Always disconnect DRB-II after use.
- Always disconnect DRB-II before charging battery.