SYMPTOM DIAGNOSIS
| CAUTION | When battery is disconnected, vehicle computer may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. |
Symptom checks cannot be used properly unless the problem occurs while the vehicle is being tested. To reduce diagnostic time, ensure steps in appropriate BASIC DIAGNOSTIC PROCEDURES and appropriate SELF-DIAGNOSTICS articles were performed before diagnosing a symptom. Following symptoms are available for diagnosis.
- «Does Not Start»(ref-121443-S23852630292001082700000)
- «Difficult To Start»(ref-121443-S32895598062001082700000)
- «Poor Idling»(ref-121443-S03345087102001082700000)
- «Poor Driveability»(ref-121443-S29637150872001082700000)
- «Engine Stalls»(ref-121443-S17325230952001082700000)
- «Refueling Problem»(ref-121443-S06183737852001082700000)
- «A/C Switch Indicator Blinking»(ref-121443-S40806079372001082700000)
INTERMITTENT PROBLEM DIAGNOSIS
Intermittent fault testing requires duplicating circuit or component failure to identify the problem. These procedures may lead to the computer setting a diagnostic trouble code (on some systems) which may help in diagnosis.
If problem vehicle does not produce diagnostic trouble code codes, monitor voltage or resistance values using a DVOM while attempting to reproduce conditions causing intermittent fault. A status change on DVOM indicates a fault has been located.
Use a DVOM to pinpoint faults. When monitoring voltage, ensure ignition switch is in ON position or engine is running. Ensure ignition switch is in OFF position or negative battery cable is disconnected when monitoring circuit resistance. Status changes on DVOM during test procedures indicate area of fault.
Wiring Harness Testing
Using DVOM, monitor suspected circuit or component. Lightly shake wiring harness while noting fluctuation in DVOM reading. Inspect wiring harness at area where it goes through the body for signs of damage.
Component, Relay & Sensor Testing
Using DVOM, monitor suspected circuit or component. Lightly vibrate suspected component, relay or sensor while noting fluctuation in DVOM reading.
Electrical Connector Testing
Using DVOM, monitor suspected circuit or component. Lightly shake electrical connector while noting fluctuation in DVOM reading. Visually inspect electrical connector for damage.
Component Testing
Heat suspected component with a hair dryer while checking for a malfunction to occur. DO NOT apply heat directly to components in Engine Control Module (ECM). DO NOT heat any component to more than 140°F (60°C).