Engine Controls - Tests W/o Codes - Eec: Diagnosis Ford Escort V facelift

SYMPTOM DIAGNOSIS

Symptom checks cannot be used properly unless the problem occurs while the vehicle is being tested. To reduce diagnostic time, ensure steps in BASIC TESTING and G - EEC TESTS W/CODES articles in the ENGINE PERFORMANCE Section were performed before diagnosing a symptom. Symptom checks are listed in order of probability, ease of accomplishment, and accessibility. Symptoms available for diagnosis are as follows

1. No Crank
2. Hard Start/Long Crank
3. Stall After Start
4. No Start/Normal Crank
5. Slow Return To Idle
6. Idle Surge, Runs Rough Or Misses
7. Fast Idle, Diesels/Runs On
8. Low/Slow Idle, Stalls/Quits
9. Stalls/Quits, Hesitation/Stumble
10. Runs Rough/Misses
11. Surge
12. Backfires
13. Loss Of Power
14. Spark Knock
15. Poor Fuel Economy
16. Emissions Compliance
17. Warning Indicator Lights
18. High Oil Consumption
19. Cooling System Runs Hot
20. Cooling System Runs Cold
21. Exhaust Smoke Or Smell
22. Fuel Odor
23. Engine Noise
24. Vibration

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 fault code which may help in diagnosis.

If problem vehicle does not produce fault 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.

Continuous Monitor Mode (Wiggle Test)

In this mode the technician can attempt to re-create an intermittent fault while monitoring the system. This mode, also called the WIGGLE TEST, may be used in Key On Engine Off (KOEO) and Key On Engine Running (KOER) self-test modes. See CIRCUIT TESTS in G - EEC TESTS W/CODES article in the ENGINE PERFORMANCE Section instructions on the use of this procedure to identify intermittent faults in specific circuits or components.

KOEO Wiggle Test

Connect test equipment. See G - EEC TESTS W/CODES article in the ENGINE PERFORMANCE Section. Turn ignition on. Activate self-test using jumper lead or diagnostic tester. Wait 10 seconds, and then deactivate and reactivate self-test to enter WIGGLE TEST. Tap, move and wiggle the suspected sensor and/or harness area. If a fault is detected, a code may be stored in memory and indicated at the diagnostic tester or Scan tool. Record or retrieve code, and perform CIRCUIT TEST indicated in CODE REFERENCE CHART table in G - EEC TESTS W/CODES article in the ENGINE PERFORMANCE Section.

KOER Wiggle Test

Connect test equipment. See G - EEC TESTS W/CODES article in the ENGINE PERFORMANCE Section. Turn ignition off, and wait 10 seconds. Start engine. Activate self-test using jumper lead or diagnostic tester. Wait 10 seconds, and then deactivate and reactivate self-test to enter WIGGLE TEST. DO NOT turn engine off. Tap, move and wiggle the suspected sensor and/or harness area. If a fault is detected, a code may be stored in memory and indicated at the diagnostic tester or Scan tool. Record or retrieve code, and perform CIRCUIT TEST indicated in CODE REFERENCE CHART table in G - EEC TESTS W/CODES article in the ENGINE PERFORMANCE Section.