Experiencing engine issues with your VW T4 and seeing the fault code 17564? This code, related to the Manifold Pressure Sensor (G71), is a common headache for VW Transporter T4 owners. Let’s dive into diagnosing and potentially resolving this problem, focusing on practical steps you can take.
When your VW T4 throws up the 17564 fault code, it signals a problem with the Manifold Absolute Pressure (MAP) sensor circuit. This sensor is crucial; it measures the pressure in the intake manifold, providing essential data to the engine control unit (ECU) for optimal fuel delivery and performance. A fault here can lead to sluggish performance, reduced boost, and even limp mode.
One common initial step is to suspect the Mass Air Flow (MAF) sensor. While not directly related to the 17564 code, a faulty MAF sensor can sometimes contribute to overall engine management issues. Replacing the MAF sensor and air filter, as a preventative measure, isn’t unreasonable, especially if they are due for replacement anyway. However, if the 17564 code persists, further investigation is needed.
The fault code 17564 specifically points to the “Manifold Pressure Sensor (G71) Open / Short to ground.” This indicates an electrical problem within the MAP sensor circuit itself, rather than a sensor malfunction in all cases. Using a diagnostic tool like VCDS or a generic OBD2 scanner is essential for reading and clearing fault codes.
Troubleshooting Steps for Fault Code 17564:
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Initial Scan and Code Clearing: Connect your OBD2 scanner to your VW T4’s OBD2 port, typically located near the steering column. Read the fault codes and note them down. Clear the codes and see if code 17564 immediately reappears. If it does, it confirms a persistent issue.
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MAP Sensor Inspection and Readings: Access the MAP sensor, usually located on the intake manifold. With the engine running and using VCDS (or a similar advanced scan tool), check the measuring blocks, specifically Group 010. Observe the readings for atmospheric pressure and boost pressure. If both readings are identical and unchanging regardless of engine RPM or load, this strongly suggests a MAP sensor or circuit issue.
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Sensor Circuit Test: Disconnect the MAP sensor electrical connector. Rescan for fault codes. You should now see fault codes related to both the MAP sensor (G71) and potentially the Manifold Temperature Sensor, as they are often integrated into the same unit. This confirms the diagnostic tool is communicating with the circuit. Reconnect the MAP sensor and clear codes again. If code 17564 returns immediately, the issue is likely within the MAP sensor itself or its wiring.
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MAP Sensor Replacement: A faulty MAP sensor is a prime suspect for code 17564. Replacing the MAP sensor is a relatively straightforward and affordable step. Ensure you source a quality replacement sensor. After replacement, clear the fault codes and test drive your VW T4 to see if the issue is resolved and boost performance is restored.
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Vacuum Hose Inspection: While the 17564 code is electrical, vacuum leaks can indirectly impact manifold pressure readings and overall engine performance. Inspect all vacuum hoses connected to the intake manifold and turbo system. Look for cracks, wear, or loose connections. Replacing old or suspect vacuum hoses with new silicone hoses is a good maintenance practice and can eliminate potential leak sources.
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Wiring Loom Inspection (Advanced): If a new MAP sensor doesn’t resolve the issue, the problem might lie in the wiring loom leading to the MAP sensor. This is a more involved step, requiring careful inspection for any breaks, shorts, or corrosion in the wiring. Consulting a wiring diagram for your VW T4 and using a multimeter to check continuity can help pinpoint wiring problems.
Conclusion:
Dealing with fault code 17564 on your Vw T4 Obd2 system requires a systematic approach. Start with basic checks like MAP sensor readings and visual inspections. Replacing the MAP sensor is often the next logical step. Don’t overlook vacuum hoses as potential contributing factors. If the problem persists, a thorough wiring inspection may be necessary. By following these steps, you can effectively troubleshoot and hopefully resolve the 17564 fault code, getting your VW T4 back to optimal running condition.
