Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Section 4 (Engine Controls - Tests W/Codes - 7.5L): Summary
If no service code or Code 11 or 111 (pass code) is present, but drive-ability problem still exists, proceed to EEC-IV DIAGNOSIS BY SYMPTOM table. If driveability problem still cannot be located, go to TESTS W/O CODES article in the ENGINE PERFORMANCE Section for diagnosis by symptoms or intermittent diagnostic procedures.
| Symptom | Application | Circuit Test |
|---|---|---|
| A/C Does Not Cut Off During WOT | All Models | KM - Step 15) |
| A/C Not Functioning | All Models | KM - Step 1) |
| Black Exhaust Smoke | Except 7.3L | H - Step 1) |
| CHECK ENGINE Light Always On | Except 7.3L | ML - Step 1) |
| CHECK ENGINE Light Flashing With Erratic Idle | Except 7.3L | ML - Step 15) |
| CHECK ENGINE Light Never On | Except 7.3L | ML - Step 4) |
| CHECK ENGINE Light On Intermittently | Except 7.3L | ML - Step 10) |
| Engine Hesitates After Hot Restart | Except 7.3L | H - Step 21) |
| Engine Hesitation | Except 7.3L | S - Step 2) |
| Engine Lacks Power or Loses Power | Except 7.3L | S - Step 2) |
| Engine Miss At Idle, Acceleration Or Cruise | Except 7.3L | S - Step 2) |
| Engine Runs Rough At All Times | Except 7.3L | S - Step 2) |
| Engine Stalls | Except 7.3L | S - Step 2) |
| Engine Stalls During Trans. Downshift | Models With A/T | TC - Step 1) |
| Engine Stalls During Trans. Engagement | Models With A/T | TC - Step 1) |
| Engine Stalls When Parking | Models With PSP Switch | FF - Step 2) |
| Engine Surge At Acceleration Or Cruise | Except 7.3L | S - Step 1) |
| Erratic RPM | Except 7.3L | S - Step 1) |
| Gasoline Fumes | Models With CANP | KD - Step 1) |
| Late Shift Into 4x4 High | Models With A/T | TB - Step 5) |
| Overdrive Cancel Indicator Off | Models With A/T | TB - Step 4) |
| 4x4 Low Light Always Off & Harsh Shift | Models With A/T | TB - Step 1) |
| 4x4 Low Light Always On & Shift Slipping | Models With A/T | TB - Step 1) |
| - On models equipped with mass airflow system, ensure air induction and electrical connections are clean and tight. | ||
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.