The OBD-II (On-Board Diagnostics II) system in your Kia vehicle is designed to monitor various components and systems to ensure optimal performance and emissions control. When a problem is detected, the system generates a Diagnostic Trouble Code (DTC) to pinpoint the issue. One such code is P1035. This article will delve into the specifics of the Kia Obdii Code P1035, its potential causes, symptoms, and troubleshooting steps.
Understanding Kia Code P1035
The Kia OBDII code P1035 typically indicates a problem with the Power Steering Pressure (PSP) switch circuit. This switch is crucial for providing the Powertrain Control Module (PCM) with information about the power steering system’s pressure. The PCM uses this input to adjust engine idle speed, especially during low-speed maneuvers like parking, where power steering demand is higher.
When the PCM detects an abnormal signal from the PSP switch circuit, either high or unchanging during self-tests, it can trigger the P1035 code. This malfunction can stem from various issues within the PSP switch circuit itself or related components.
Symptoms of a P1035 Code
While a P1035 code is active, you might observe several symptoms in your Kia, including:
- Check Engine Light is illuminated: This is the most common and immediate symptom.
- Rough or unstable idle: The engine idle speed might fluctuate or feel rough, particularly when turning the steering wheel.
- Stalling at low speeds: In some cases, the engine might stall when making sharp turns at low speeds, such as during parking.
- Power steering malfunction (potentially): Although less directly related, issues with the PSP switch could in some scenarios indirectly affect power steering performance, though this is less common.
Potential Causes of Kia P1035
Several factors can contribute to the triggering of the P1035 code in your Kia vehicle:
- Faulty Power Steering Pressure (PSP) Switch: The switch itself might be defective, sending incorrect or no signals to the PCM.
- PSP Switch Circuit Issues: This includes:
- Damaged PSP switch/shorting bar: Physical damage to the switch or its connector.
- SIG RTN (Signal Return) circuit open: A break in the signal return wire.
- PSP circuit open or shorted to SIGRTN: A break or short circuit in the PSP signal wire.
- Wiring Harness Connector Problems: Particularly in areas prone to moisture intrusion, such as:
- Body harness connector: Located around the left-hand kick panel area or inside the Instrument Panel (IP). Water leaks from clogged sunroof drains, A-pillar leaks, or windshield/cowling leaks can affect this connector.
- PCM (Powertrain Control Module) Malfunction: In rare cases, the PCM itself could be faulty, misinterpreting signals or incorrectly diagnosing the PSP switch circuit.
Troubleshooting and Repairing P1035
Diagnosing and repairing the P1035 code typically involves a systematic approach:
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Initial Inspection:
- Visually inspect the PSP switch and its wiring for any obvious damage, corrosion, or loose connections.
- Check the wiring harness connector in the kick panel area for signs of water intrusion or corrosion.
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PSP Switch Testing:
- Use a multimeter to test the PSP switch for proper continuity and resistance according to the Kia service manual for your specific model.
- Check if the switch changes state when power steering pressure is applied (e.g., when the steering wheel is turned).
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Circuit Testing:
- Test the SIG RTN and PSP circuits for continuity, shorts to ground, and shorts to voltage using a multimeter.
- Refer to wiring diagrams in the Kia service manual to identify the correct pins and wiring paths.
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PCM Input Verification:
- Using a scan tool, monitor the PSP switch input signal to the PCM while turning the steering wheel.
- Verify if the signal changes as expected. If not, and the switch and wiring are confirmed to be good, a PCM issue might be suspected (though less likely).
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Repair and Component Replacement:
- Based on the diagnosis, repair any identified wiring issues (shorts, opens, corrosion).
- Replace the PSP switch if it is found to be faulty.
- If water intrusion is found in the harness connector, clean and dry the connector thoroughly and address the source of the leak.
- PCM replacement should only be considered as a last resort after all other possibilities have been ruled out.
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Code Clearing and Verification:
- After completing repairs, clear the P1035 code using an OBD-II scan tool.
- Perform a test drive to ensure the code does not return and that the symptoms are resolved.
Important Note: While this guide provides general troubleshooting steps, always refer to the specific Kia service manual for your vehicle model for detailed procedures, wiring diagrams, and component specifications. If you are not comfortable performing electrical diagnostics and repairs, it is recommended to seek assistance from a qualified automotive technician.
By understanding the nature of the Kia OBDII code P1035 and following a structured diagnostic approach, you can effectively troubleshoot and resolve this issue, ensuring the proper functioning of your Kia’s power steering system and overall vehicle performance.
