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.
Code 2-4-1 (EGR System)
Turn ignition on. Press button on diagnostic unit 3 times. Each time hold for one second. LED should begin to flash at same rate as EGR converter is energized. Connect ohmmeter between terminals No. 6 (Blue wire on all models) and 15 (White/Black wire on 240; Red/Green wire on 740/940). Resistance should be 85 ohms.
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.