Auto Start-Stop Restart Failure
2009-2012 Ford Flex 3.5L V6
Description
The engine failed to restart after an auto start-stop event. The starter engaged but the engine did not reach running speed or stalled immediately.
Symptoms
- Engine did not restart at green light
- Starter cranking prolonged after stop
- Dashboard warning lights illuminated
- Vehicle rolled in traffic
- Hazard situation created
Common Causes
- Starter motor degradation
- Fuel pressure drop during stop
- Engine position sensor error
- Low battery voltage during crank
- Intake manifold vacuum leak
Diagnostic Steps
- Check starter motor engagement force
- Monitor fuel pressure during and after stop
- Test battery voltage during restart crank
- Check engine position sensor signal
- Inspect intake manifold for vacuum leaks
Repair Notes
Replace starter motor if engagement count is high. Check fuel system for pressure retention. Critical safety issue - disable start-stop until resolved.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P3601 on Other Vehicles
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Ford Bronco
2021-2024 2.7L V6 EcoBoost
Ford Bronco Raptor
2022-2024 3.0L V6 EcoBoost
Ford Bronco Sport
2021-2024 1.5L I3 EcoBoost
Ford Bronco Sport
2021-2024 2.0L I4 EcoBoost
Ford Crown Victoria
1998-2011 4.6L V8 Modular 2V
Ford E-150
1997-2014 4.6L V8 Triton
Ford E-150
1997-2014 5.4L V8 Triton
Common Questions
What does code P3601 mean on a 2009-2012 Ford Flex?
P3601 stands for "Auto Start-Stop Restart Failure". The engine failed to restart after an auto start-stop event. The starter engaged but the engine did not reach running speed or stalled immediately.
What are the symptoms of P3601 on a Ford Flex?
Common symptoms of P3601 include: Engine did not restart at green light, Starter cranking prolonged after stop, Dashboard warning lights illuminated, Vehicle rolled in traffic, Hazard situation created.
What causes P3601 on a 2009-2012 Ford Flex?
Common causes of P3601 include: Starter motor degradation, Fuel pressure drop during stop, Engine position sensor error, Low battery voltage during crank, Intake manifold vacuum leak.