Engine Controls - Tests W/O Codes: Introduction
Before diagnosing symptoms or intermittent faults, perform preliminary inspection and self-diagnostic steps in the appropriate TESTS W/CODES article. Use this article to diagnose driveability problems existing when a hard trouble code is not present.
NOTE:
Some driveability problems may have been corrected by manufacturer with a revised computer calibration chip or Powertrain Control Module (PCM). Check with manufacturer for latest chip or PCM application.
Symptom checks can direct the technician to malfunctioning component(s) for further diagnosis. A symptom should lead to a specific component, system test or adjustment. See SYMPTOMS .
Use intermittent test procedures to locate driveability problems that do not occur when the vehicle is being tested. These test procedures should also be used if a soft (intermittent) trouble code was present but no problem was found during self-diagnostic testing. See INTERMITTENTS .
NOTE:
For specifications, see the ADJUSTMENTS
article or the SPECIFICATIONS
article. For specific testing, see the appropriate SYSTEM/COMPONENT TESTS
article.