Jeep Fault Code
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Misfire under load; Engine "stumbling" at highway speeds.
System
Not specified
Symptom
Misfire under load; Engine "stumbling" at highway speeds.
Diagnosis & fix steps
Injector Control Circuit.
LOGIC: The PCM is not seeing the expected inductive "kick" from one or more fuel injectors.
ACTION: 1. Use a "Noid Light" to check for pulse at each injector.
2. Measure injector resistance (should be approx. 12-14 Ohms).
FIX: Replace the faulty Fuel Injector or repair the injector harness.
Red Seal field insights
The injector harness on the 4.0L sits right over the hot intake manifold. Over time, the plastic looms crack, and the wires can short together. Check the harness specifically near the rear of the head.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
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