A 2009 Acura TSX with 145,000 miles on the chassis and a 70,000-mile engine is experiencing intermittent starting problems and limp mode. The engine runs smoothly, but starting can be inconsistent, sometimes requiring extended cranking. When this occurs, VSA, emissions, and power steering warning lights illuminate, indicating limp mode. Power steering typically returns after a minute, but the warning lights and limp mode persist. Clearing the codes temporarily resolves the issue, but the problem reoccurs within a few days. Previously recorded codes include 83-1 and 22-01, alongside a misfire caused by a faulty crank sensor.
Troubleshooting Steps Taken
Several components have been replaced in an attempt to resolve the issue:
- Spark Plugs: New spark plugs have been installed.
- Starter Motor: The starter motor has been replaced twice, both times with non-OEM parts. The first replacement occurred with the original engine, and the second with a replacement engine.
- Crank Sensor: A new, non-OEM crank sensor has been installed.
- Evap Purge Valve: A new, non-OEM evap purge valve has been installed.
- Battery: The battery has been replaced.
- Alternator: The alternator has been tested and is functioning correctly.
Additional Diagnostic Checks
Beyond component replacement, the following checks have been performed:
- Ground Connections: All ground connections have been cleaned.
- Fuel Pressure: Fuel pressure has been tested and is within the acceptable range.
- Oil Level: The engine oil level is at the correct level.
- Engine Harness: Connections on the engine harness have been inspected.
Potential Causes and Further Diagnosis
A key question is whether the use of non-OEM starters might be contributing to the problem, given the known compatibility issues some vehicles have with aftermarket parts. Further investigation should focus on:
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Starter Compatibility: Verify the compatibility of the non-OEM starters with the 2009 Acura TSX. Consult online forums, repair manuals, or contact an Acura dealership for confirmation. Using an Elm327 Usb Interface Obdii Obd2 Diagnostic Auto Car Scanner can provide real-time data during starting to pinpoint any voltage drops or communication errors.
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Electrical System Diagnosis: Perform a thorough electrical system diagnosis using a multimeter to check for voltage drops, resistance, and continuity in key circuits related to the starting system, VSA, emissions, and power steering. Focus on the wiring and connectors associated with the starter, crank sensor, and related components. An ELM327 scanner can help monitor live data from these systems.
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CAN Bus Communication: The intermittent nature of the problem suggests a possible issue with communication on the Controller Area Network (CAN) bus. An ELM327 USB interface can be used to monitor CAN bus traffic for errors or inconsistencies.
Conclusion
The persistent starting and limp mode issues on this 2009 Acura TSX require a systematic diagnostic approach. While several components have been replaced, focusing on starter compatibility, detailed electrical system testing, and CAN bus communication analysis using an ELM327 USB interface OBDII OBD2 diagnostic auto car scanner is crucial for identifying the root cause and implementing a lasting solution.
