Engine Controls - Introduction - Diesel: Diagnosis Ford Econoline E250

Diagnostic Methods Article

The DIAGNOSTIC METHODS - 6.0L DIESEL article contains information on specific diagnostic tasks that are used during diagnosis. Descriptions of specific diagnostic methods are included, as well as detailed instructions on how to access or perform the tasks. This article provides the technician with step-by-step instructions for performing routine diagnostic tasks.

Symptom Charts Article

All diagnosis begins in the SYMPTOM CHARTS - 6.0L DIESEL article with the Symptom Index. The Symptom Index contains the list of symptoms addressed in this article. The Symptom Index will refer the technician to the appropriate Symptom chart, which guides the technician through diagnosis.

Diagnostic Subroutines Article

The DIAGNOSTIC SUBROUTINES - 6.0L DIESEL article contains the Hard Start/No Start and Performance Diagnostic Procedures that are used to obtain quick diagnostic information. This article also contains the Powertrain Diagnostic Trouble Code (DTC) "Go To" Charts. The SYMPTOM CHARTS article will direct the technician to these tests when required.

How To Use The Diagnostic Procedures

1. Use the information about the vehicle driveability or emission concern (from the service write-up, Customer Information Worksheet, etc.) to attempt to verify/re-create the symptom. Look for any vehicle modifications or aftermarket items that may contribute to the symptom. A check of any applicable TSBs if this information is available.
2. Refer to the «SYMPTOM CHARTS - 6.0L DIESEL»(ref-225539) and select the symptom that best describes the vehicle symptom. (For multiple symptoms, select the one that is most noticeable.)
3. Go to the Symptom Chart indicated in the SYMPTOM CHARTS article.
4. Begin the Chart at step number "1."
5. Follow the instructions in the step (including Preliminary Checks, etc.) If the step contains a test procedure or question (without a reference outside the step), perform the test step/answer the question and continue as directed. If the step sends you to a specific area for testing (for example Hard Start/No Start Procedures, a Pinpoint Test Step in PINPOINT TEST article), go to the procedures. Follow the directions given in those procedures, including directions to other tests, articles. If a damaged part is found, repair/replace as directed. If no fault is found and diagnosis in that area is complete, return to the SYMPTOM CHART article and continue as directed.
6. During diagnosis, if directed to test a system/component that is not contained on that vehicle, proceed to the next step.
7. If the Symptom Chart for the vehicle symptom is completed and no fault is found, return to the Symptom Index to address the next most prominent symptom.
8. After service, verify that the vehicle is operating properly and the original complaint is eliminated.

Note. If a symptom is determined to be intermittent, careful visual and physical underhood inspection of connectors, wiring harnesses, vacuum lines, and components is required. The Customer Information Worksheet may contain more detailed symptom information. Before an in-depth diagnosis begins, start the engine and wiggle wires, tap on components, etc., while listening for an indication of a concern (such as RPM change or relay clicking).

Information about engine conditions is stored when a Diagnostic Trouble Code (DTC) that illuminates the Malfunction Indicator Lamp (MIL) is set.