A 2012 Audi A4 B8 with a GAS TFSI engine is experiencing an illuminated EPC light and throwing the following fault codes: P0343 (Camshaft Position Sensor Signal High), P2014 (Intake Manifold Runner Position Sensor Circuit), and P2016 (Intake Manifold Position Sensor Low). This article will explore potential causes and troubleshooting steps, leveraging Vcds Cam Speed Measurement capabilities for diagnosis.
While the P2014 code was mentioned initially, the provided VCDS log only shows P0343 and P2016. Therefore, we’ll focus on these two codes. The owner has already replaced several components, including the camshaft position sensor, intake manifold runner position sensor, fuel injector o-rings, and spark plugs. A carbon cleaning and intake manifold replacement were performed previously.
Understanding the Fault Codes and VCDS Cam Speed Measurement
P0343 – Camshaft Position Sensor (G40) Signal Too High: This code indicates an issue with the camshaft position sensor signal. A high signal could suggest a wiring problem, a faulty sensor (despite replacement), or an issue with the sensor’s power supply. VCDS can measure camshaft speed and compare it to crankshaft speed to identify discrepancies that might point to sensor malfunction or timing issues.
P2016 – Intake Manifold Flap Position Sensor (Bank 1) Short to Ground: This code points to a short circuit in the wiring for the intake manifold flap position sensor. This could be caused by damaged wiring, a faulty sensor, or a problem within the engine control module (ECM).
Troubleshooting Steps Using VCDS
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Verify Wiring and Connections: Carefully inspect the wiring harnesses connected to both the camshaft position sensor and the intake manifold flap position sensor. Look for any signs of damage, such as fraying, chafing, or exposed wires. Pay close attention to the area where the owner found missing insulation on the knock sensor connector wiring, as this could indicate a broader wiring issue in that vicinity. Use VCDS’s measuring block function to monitor live data from the sensors while manipulating the wiring harness. Any fluctuations in the readings could pinpoint the location of the fault.
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Check Sensor Power Supply: Using VCDS, check the voltage supply to both sensors. Ensure they are receiving the correct voltage and ground. A low or fluctuating voltage could cause erratic sensor behavior. Refer to the vehicle’s wiring diagram for specific voltage specifications.
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Perform VCDS Cam Speed Measurement: Compare the camshaft speed reading from VCDS to the expected value. A significant deviation could indicate a problem with the camshaft timing or the sensor itself, even if it’s new. This test helps rule out a faulty sensor as the root cause of the P0343 code.
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Analyze Freeze Frame Data: The VCDS log provides freeze frame data, capturing the engine’s operating conditions when the fault codes were triggered. Pay close attention to parameters like engine RPM, load, and temperature. This information can offer clues about the circumstances under which the faults occur. For instance, if the fault occurs consistently at low RPM, it might point to a specific operating condition triggering the issue.
Conclusion
Troubleshooting intermittent electrical faults can be challenging. Utilizing VCDS’s diagnostic capabilities, specifically cam speed measurement and live data monitoring, is crucial for pinpointing the root cause of the P0343 and P2016 codes in this 2012 Audi A4. Thoroughly inspecting the wiring, verifying power supply, and analyzing freeze frame data will help narrow down the possibilities and guide further repairs. If the issue persists after these steps, consider seeking professional assistance from an experienced Audi technician.
