Engine Starts Then Dies Immediately
The engine cranks and starts but stalls right away, indicating a fuel, air, or security system issue. This is a common problem on the 2020 Jeep Grand Cherokee, often related to the fuel pump, anti-theft system, or a vacuum leak.
Diagnosis Details
Possible Causes
Faulty fuel pump or fuel pump relay – insufficient fuel pressure causes the engine to start on residual pressure then stall.
Anti-theft system (SKIM) malfunction – the immobilizer may not recognize the key, cutting fuel or spark after start.
Vacuum leak (e.g., cracked intake hose or PCV valve) – unmetered air causes a lean condition and stalling.
Crankshaft position sensor failure – the PCM loses engine position signal, causing immediate stall.
Related OBD-II Codes
Not satisfied with this diagnosis?
Try Another DiagnosisWhat To Do Next
What You Should Do
Check for diagnostic trouble codes (DTCs) with a scan tool.
Listen for fuel pump prime (2-second hum at key on).
Test fuel pressure (should be 55-60 psi).
Inspect for vacuum leaks.
If no codes, try a second key to rule out immobilizer issue.
If fuel pressure is low, replace fuel pump or relay.
Related Repairs
Share this diagnosis
Help others with similar symptoms
Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.
