A 2006 MK5 GTI recently remapped to stage 1 experienced a performance decrease shortly after the upgrade. Prior to the remap, the vehicle owner noted recurring Diagnostic Trouble Codes (DTCs) that were initially disregarded. This article examines these DTCs retrieved using Vcds 805.1 Full Version and explores potential causes and solutions. The car exhibits poor fuel economy, achieving approximately 250 miles on a full tank, primarily driven on short journeys. Previous attempts to improve fuel efficiency, such as replacing the Diverter Valve (DV), Positive Crankcase Ventilation (PCV) with a BSH Revamp, and installing Denso IK24 spark plugs, proved unsuccessful.
Decoding the VCDS 805.1 Scan
The following data was retrieved using VCDS 805.1 Full Version, providing critical insights into the GTI’s engine performance issues:
Friday,04,November,2011,22:33:27:26365
VCDS Version: Release 805.1
Data version: 20080823
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Address 01: Engine Control Module
Part Number: 1K0 907 115 J
Component and/or Version: 2.0l R4/4V TFSI 0030
Software Coding: 0403000318070060
Work Shop Code: WSC 001912
Faults Found:
012599 - Intake Manifold Runner Control: Basic Setting not Completed
P3137 - 001 - Upper Limit Exceeded - Intermittent
Freeze Frame:
RPM: 0 /min
Load: 0.0 %
Speed: 0.0 km/h
Temperature: 55.0°C
Temperature: 43.0°C
Absolute Pres.: 990.0 mbar
Voltage: 12.065 V
001602 - Sensor Reference Voltage A: Circuit: Low
P0642 - 002 - Lower Limit Exceeded - Intermittent - MIL ON
Freeze Frame:
RPM: 0 /min
Load: 0.0 %
Speed: 0.0 km/h
Temperature: 55.0°C
Temperature: 43.0°C
Absolute Pres.: 990.0 mbar
Voltage: 12.192 V
Readiness: 0000 0000Analyzing the Fault Codes: P3137 and P0642
The VCDS 805.1 scan reveals two key fault codes:
P3137 – Intake Manifold Runner Control: Basic Setting not Completed: This code suggests a problem with the intake manifold runner control system. This system adjusts the length of the intake runners to optimize engine performance and fuel efficiency at different RPMs. A malfunctioning intake flapper motor, a common issue in these engines, could be the culprit.
P0642 – Sensor Reference Voltage A: Circuit Low: This code indicates a problem with the reference voltage supplied to various sensors in the engine. This low voltage can disrupt sensor readings, leading to performance issues and potentially triggering other fault codes. Possible causes include a faulty sensor ground, wiring issue, or a problem with the power supply to the sensors.
Potential Solutions and Next Steps
Given the DTCs and symptoms, several diagnostic steps are recommended:
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Intake Manifold Runner Control: Inspect the intake manifold runner control system, including the intake flapper motor and its associated linkage and wiring. Check for any binding, damage, or loose connections. A VCDS 805.1 Full Version can be used to perform a basic setting or adaptation of the intake manifold runner control system after any repairs.
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Sensor Reference Voltage: Thoroughly check the wiring and connections related to the sensors using the wiring diagram specific to the 2006 MK5 GTI. Measure the reference voltage at various sensor connectors to pinpoint the source of the low voltage.
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Fuel Economy: While the DTCs may contribute to poor fuel economy, the short distance journeys could also be a major factor. Continue monitoring fuel consumption after addressing the DTCs to assess improvement.
The VCDS 805.1 Full Version scan provides a valuable starting point for diagnosing the performance and fuel economy issues in this MK5 GTI. Further investigation is necessary to determine the root cause and implement the appropriate repairs.
