17.2 LOW HORSEPOWER INTERVIEW 17.2.1.1 Driver Questionnaire Ask the driver to answer the following questions before attempting to repair an intermittent problem, or a problem with symptoms but no diagnostic codes. Use this and the response as a guideline. Refer to section 17.2.1.2, “Questionnaire Response Guideline.” 1. How often does the problem occur? Can you and the driver take the vehicle and demonstrate the problem in less than 30 minutes? 2. Has the vehicle been to other shops for the same problem? If so, what was done there? 3. Did the radio, dash gages, or lights momentarily turn OFF when the problem occurred? 4. Does the problem occur only at specific operating conditions?
If so, at what load? Is it light, medium, or heavy? 5. Does the problem occur at a specific engine operating temperature? If so, at what engine temperature? 6. Does the problem occur at a specific engine operating altitude? If so, at what altitude? 7. Does the problem occur only when above or below specific outside temperatures? If so, what temperature range? 8. Does the problem occur during other conditions e.g. during or after rain, spray washing, snow? 9. Did the problem occur at a specific vehicle speed? If so, at what vehicle speed? 10. Does the problem occur at specific engine RPM? If so, at what engine RPM?
17.2.1.2 Questionnaire Response Guideline The following are typical responses to the driver questionnaire: PERSONAL INJURY To avoid injury from loss of vehicle/vessel control, the operator of a MBE electronic controlled engine must not use or read any diagnostic tool while the vehicle/vessel is moving. 1. If the problem is repeatable, take the vehicle for a drive with Detroit Diesel Diagnostic Link (DDDL) connected and note the conditions when the problem occurs. Be prepared to take snapshot data using DDDL. Ensure you operate the vehicle after correcting the problem and duplicate the operating conditions before releasing the unit, in order to verify the problem is corrected. 2.
If the vehicle has been to other shops for the same problem, call the other shops and find out what has been done. Avoid replacing the same components again unless absolutely (Rev. 2007) All information subject to change without notice. 17-8 From Bulletin 1–MBE 4000–07 6SE412 0702 Copyright © 2007 DETROIT DIESEL CORPORATION