A Skoda Yeti owner experienced a sudden loss of acceleration, followed by multiple warning lights illuminating the dashboard. The vehicle drives normally otherwise. A VCDS scan revealed fault codes in the ABS, Haldex 4WD system, and steering modules. This article analyzes these codes and offers potential solutions for using VCDS to diagnose the issue.
Understanding the VCDS Skoda Yeti Fault Codes
The VCDS scan reveals several interconnected faults within the Skoda Yeti’s systems:
ABS System Faults:
- 00668 – Supply Voltage Terminal 30: This code indicates a low voltage issue at terminal 30, which supplies power to various components, including the ABS system. This could be caused by a faulty battery, alternator, or wiring issue.
- 00290 – ABS Wheel Speed Sensor; Rear Left (G46): This code appears twice, suggesting a problem with the rear left wheel speed sensor. The descriptions point to both mechanical (003) and electrical (012) faults, which could mean a damaged sensor, wiring harness, or corroded connector.
- 03841 – RPM Sensor Rear Left: Incorrect Signal: This code reinforces the suspicion of a faulty rear left wheel speed sensor, as it directly relates to the rotational speed signal from that wheel.
Haldex 4WD System Faults:
- 16670 – All-Wheel Drive C1113: A mechanical failure within the Haldex system. This could be related to the Haldex pump, control unit, or a mechanical issue within the differential itself.
- 16656 – Databus U1123: This code signifies a communication error on the vehicle’s databus. This suggests that the Haldex module isn’t communicating correctly with other control units, possibly due to the ABS issue.
Steering Assist Fault:
- 01316 – ABS Control Module: This code within the steering assist module indicates a problem detected with the ABS module. This further highlights the interconnected nature of the faults and points towards the ABS system as the root cause.
Using VCDS Skoda Yeti to Pinpoint the Problem
While the steering fault might be unrelated due to its older timestamp, the ABS and Haldex faults appear interconnected. The following steps using VCDS can help pinpoint the problem:
- Check Measuring Values: Use VCDS to monitor the live data stream from the rear left wheel speed sensor (Group 001 in ABS module). Compare its readings with the other wheel speed sensors while driving. A significant deviation or erratic signal confirms a sensor issue.
- Wiring Harness Inspection: Thoroughly inspect the wiring harness leading to the rear left wheel speed sensor for damage, chafing, or corrosion. Pay particular attention to the connector.
- Test Voltage at Terminal 30: Use a multimeter to measure the voltage at terminal 30 with the engine running. It should be around 14 volts. A lower reading confirms the low voltage fault and requires further investigation of the battery and alternator.
Conclusion
The multiple fault codes in the Skoda Yeti suggest a likely issue with the rear left wheel speed sensor and a potential low voltage problem. Using VCDS to examine live data, inspect wiring, and verify voltage will help confirm the diagnosis and guide the repair process. Addressing the ABS issue will likely resolve the associated Haldex and potentially the steering faults. Further diagnostics might be needed if the issues persist after addressing the suspected primary causes.
