Owner's Problem Description
The owner reports that their 2007 Chrysler Sebring experiences intermittent stalling, unable to exceed 40 mph. The electrical problem light illuminated on the dashboard during these episodes. Previous actions include charging the battery overnight after AutoZone indicated it was bad. The owner is seeking advice on potential causes before driving the vehicle for inspection.
Professional Technical Analysis
The 2007 Chrysler Sebring, featuring a 2.4L inline-4 engine and an automatic transmission, is experiencing intermittent stalling, especially when accelerating past 40 mph. The vehicle has approximately 120,000 miles on the odometer. The electrical system warning light has been activated, indicating potential issues within the system. A review of the vehicle’s repair history reveals a recent battery issue, where the battery was reported bad by AutoZone, suggesting potential electrical system inefficiencies. The stalling could be related to inadequate fuel delivery, ignition system failure, or voltage regulation issues. Voltage fluctuations below 13.8V could adversely affect the PCM, leading to erratic fuel injector behavior and misfires. Additionally, a faulty MAP sensor could cause improper fuel management, exacerbating stalling symptoms. The vehicle's current condition raises safety concerns, as stalling at speed can lead to loss of control. Essential diagnostic steps include verifying battery voltage under load (should be 12.4V+ at rest, 13.8-14.4V during engine operation), assessing fuel pressure (specifications at 35-45 PSI), and examining the integrity of electrical connections for corrosion or wear. Documenting any fault codes retrieved during diagnostics will guide further troubleshooting and repairs.
Possible Causes
Most common causes (ordered by frequency):
- Battery and Charging System Failure: The owner reported issues with the battery, which AutoZone indicated as bad. If the battery is not holding a charge, it can lead to insufficient power supply to the PCM and other systems, causing stalling. Voltage should be maintained between 13.8-14.4V during engine operation. Confirm battery voltage under load and check the alternator output to ensure proper functioning. - Electrical problem light illuminated, battery reported bad by AutoZone, voltage fluctuations during operation.
- Fuel System Issue: The stalling could be due to insufficient fuel pressure, which should range from 35-45 PSI. A failing fuel pump or clogged fuel filter can cause drops in pressure, leading to stalling under load. Testing the fuel pressure at the fuel rail will confirm if the system is functioning correctly. - Stalling under acceleration, bogging down, potential fuel delivery issues.
- Ignition System Malfunction: A malfunctioning ignition control module or faulty spark plugs could lead to misfiring, causing the engine to stall. The ICM should be tested for proper operation, and spark plug resistance should be within 5,000-15,000 ohms. If the ignition system is not functioning properly, it could directly affect engine performance. - Intermittent stalling, check engine light not illuminated, potential stored codes related to ignition.
- Manifold Absolute Pressure (MAP) Sensor Failure: A faulty MAP sensor may provide incorrect readings to the PCM, leading to improper fuel mixture and engine stalling. The sensor should output approximately 1V at idle and increase under load. Testing the MAP sensor will confirm its proper operation. - Poor engine performance, hesitation during acceleration, possible MAP sensor codes.
Diagnostic Steps
Professional Diagnosis Process
Follow these systematic steps to accurately diagnose the issue. Each step builds on the previous one to ensure accurate diagnosis.
- STEP 1 - Initial OBD-II Diagnosis: Use a professional OBD-II scanner or GeekOBD APP to retrieve any stored codes and freeze frame data. This will help identify any current or past issues related to the vehicle's electrical systems. Pay attention to any fault codes related to the battery, PCM, or fuel system.
- STEP 2 - Battery and Charging System Check: Test the battery voltage under load and check the alternator output. The battery should maintain at least 12.4V at rest and 13.8-14.4V during engine operation. If the voltage is low, consider replacing the battery and testing the alternator for proper output.
- STEP 3 - Fuel Pressure Testing: Connect a fuel pressure gauge to the fuel rail and verify that the pressure is within the specified range of 35-45 PSI. If the pressure is low, inspect the fuel pump and filter for issues. This step is crucial to ensure adequate fuel delivery to the engine.
- STEP 4 - Ignition System Inspection: Check the ignition control module and spark plugs for proper function. Measure the resistance of the spark plugs to ensure they are within specification (5,000-15,000 ohms). If there are any signs of wear or failure, replace the components as necessary.
