Jeep Fault Code
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Engine cranks but won't start; Sudden stalling when hitting bumps; No spark.
System
Not specified
Symptom
Engine cranks but won't start; Sudden stalling when hitting bumps; No spark.
Diagnosis & fix steps
No Crank Reference Signal.
LOGIC: The PCM is not seeing a signal from the Crankshaft Position Sensor (CPS) while the engine is turning.
ACTION: 1. Check the CPS connector at the back of the engine (near the firewall).
2. Inspect the CPS wiring for heat damage from the exhaust manifold.
FIX: Replace the Crankshaft Position Sensor.
Red Seal field insights
The CPS is located on the driver-side bellhousing. It is notorious for failing when hot. If your Jeep dies after 20 minutes of driving but starts back up when cool, the CPS is the prime suspect.
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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