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.
1989 Ford Bronco II 4WD, Standard, M5OD-R1FACTORY OEM SERVICE PROCEDURE
2.9L CEC Tests W/Codes
- Diagnosis & Testing
- Quick Test
- Description
- Visual Check & Vehicle Preparation
- Equipment Hook-Up
- Key On Engine Off (KOEO) Self-Test
- Key On Engine Off (KOEO) Codes
- Computed Timing Check
- Key On Engine Running (KOER) Self-Test
- Key On Engine Running (KOER) Codes
- Continuous Self Test
- Continuous Monitor Mode (Wiggle Test)
- Diagnosis By Symptom
- Continuous Codes
- Diagnostic Aids
- ECA Pin Voltage & Resistance Checks
- Frequently Used EEC-IV Abbreviations
- Service Code Definitions
- Circuit Test
- Connector Pin Identification
- How To Use Circuit Tests
- Test A1 - No Start
- Test A2 - Vehicle Battery
- Test A3 - Ref. Voltage
- Test B1 - Vat Sensor
- Test B2 - Act Sensor
- Test B4 - EVP, EGRC, EGRV
- Test B5 - ECT Sensor
- Test B6 - Map/BP Sensor
- Test B7 - Knock Sensor
- Test B8 - TPS
- Test B10 - PFE, EVR
- Test B11 - EVP, EVR
- Test B12 - VSS
- Test B13 - NDS & A/C
- Test B14 - Boo Switch
- Test B15 - PSPS
- Test B16 - Rpm Sensor
- Test B17 - FIPL Sensor
- Test C1 - Fuel Control
- Test C2 - Inertia Switch
- Test D1 - EGR On/Off
- Test D3 - Air System
- Test D4 - Canister Purge
- Test D5 - ISC
- Test D6 - SIL
- Test D7 - WAC
- Test D8 - Octane Adjust
- Test D10 - Dynamic Response
- Test D11 - Check Engine
- Test D12 - IDM
- Test D13 - Spark Timing
- Test D14 - No Codes
- Test D15 - KOEO Code 15
- Test D16 - Output State
- Test D17 - Re-Initialization
- Test D19 - System Check
- Test D22 - A4LD Trans
- Test D25 - E4OD Trans
- Wiring Diagrams
Factory Service Tools
Use the Manual With the Right Hardware
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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.
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