OBD-II DTC P1402 – System Voltage Out Of Self Test Range
DTC P1402 meaning
DTC P1402 refers to a diagnostic trouble code indicating that the system voltage is out of the self-test range during the vehicle’s onboard diagnostics II (OBD-II) testing. This code typically suggests that the voltage levels detected by the engine control module (ECM) are either too high or too low, which can affect the performance of various vehicle systems.
DTC P1402 symptoms
Common symptoms associated with DTC P1402 may include:
- Illumination of the check engine light
- Erratic engine performance
- Difficulty starting the engine
- Increased fuel consumption
- Potential stalling or misfiring
DTC P1402 causes
Several factors can lead to the triggering of DTC P1402, including:
- Faulty battery or charging system
- Corroded or loose electrical connections
- Defective voltage regulator
- Malfunctioning ECM
- Wiring issues, such as shorts or breaks in the harness
DTC P1402 seriousness
The seriousness of DTC P1402 can vary based on the underlying cause. While it may not immediately affect drivability, it can lead to more significant issues if left unaddressed. Continuous operation with this code may result in:
- Increased wear on engine components
- Potential damage to the electrical system
- Failure to pass emissions tests
How to diagnose DTC P1402
To diagnose DTC P1402, follow these steps:
- Use an OBD-II scanner to confirm the presence of the code.
- Check the vehicle’s battery and charging system for proper voltage levels.
- Inspect all related wiring and connectors for signs of damage or corrosion.
- Test the voltage regulator to ensure it is functioning correctly.
- Examine the ECM for any faults or software issues.
How to fix DTC P1402 step-by-step instructions
To fix DTC P1402, follow these step-by-step instructions:
- Disconnect the battery to ensure safety while working on the electrical system.
- Inspect and clean all battery terminals and connections.
- Test the battery and charging system replace any faulty components.
- Check the wiring harness for damage
Recommended tools for OBD-II diagnostics
Explore our expert picks: The Best OBD2 Scanners for 2025
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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