A Volkswagen Scirocco came into TEC AUTO with a persistent P0098 fault — Intake Air Temperature Sensor 2 Circuit High. The owner had already replaced the sensor once. The light came back within days.

That’s a pattern we see regularly. Car goes to a shop, gets a part replaced, drives away, and the same fault is back a week later. Sometimes it’s not the part. Sometimes it’s what’s feeding the part.

What P0098 Actually Means

P0098 flags when the intake air temperature sensor is reading too high — above what the ECU expects given the current conditions. Most workshops see that code, replace the IAT sensor 2, and call it done. On many cars, that works. On this Scirocco, it didn’t.

When we connected it to VCDS — Volkswagen’s own diagnostic system — and did a full inspection, we found a broken wire in the harness leading to the sensor. The wire was damaged enough to send a bad signal to the ECU, which logged the fault. The sensor itself was reading correctly. The problem was upstream.

Why the Parts Replacement Didn’t Work

Replace a working sensor and you’re changing something that isn’t broken. Fault codes tell you where the signal went wrong — not always which component caused it. Real diagnosis means tracing the fault to its source, not just swapping whatever the code points to.

In this case, the broken wire was generating the fault signal. A third sensor replacement wouldn’t have fixed it either.

The Repair: $30

Once we located the damaged wire and repaired the harness, the fault cleared. It hasn’t returned. Total cost to the customer: $30.

This is the difference between parts-swapping and actual diagnosis. A proper check before touching any components saves time, money, and repeat trips to the workshop.

Volkswagen Diagnostics at TEC AUTO

We use VCDS — the same diagnostic platform Volkswagen’s authorised workshops use — to read live data, fault histories, and sensor values across the full vehicle network. It gives us the same visibility as a VW dealership technician, without the dealership bill.

If your VW has a fault code that keeps coming back after a repair, bring it in. We’ll trace it properly before touching anything.

📍 60 Jln Lam Huat #04-61/62, Carros Centre, Woodlands
📞 +65 9339 2769  |  WhatsApp us