ADVICE CENTRE // KNOWLEDGE
The JVS Advice Centre
Genuinely useful automotive technical knowledge — written by people who do the work, not content farms. Topics that relate to the real vehicles and faults we see in Telford and Shropshire.
VW GROUP DIAGNOSTICS & REPAIRS // 2026-10-28 // 2 min read
VW Group Keyless Entry Faults — "Key Not Detected" Explained
"Key not detected" on a VW, Audi, Škoda or SEAT is often a door or interior antenna fault rather than a flat fob. Here's the order to check things in, including the emergency start procedure.
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VW GROUP DIAGNOSTICS & REPAIRS // 2026-10-28 // 2 min read
VW Group Turbo Overboost and Limp Mode — VNT, Actuator and Boost Faults
Overboost limp mode that clears on restart on a VW Group TDI is usually a sticking VNT mechanism or actuator fault, not a failed turbo. Here's how the two are told apart — and why it matters for cost.
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VW GROUP DIAGNOSTICS & REPAIRS // 2026-10-28 // 2 min read
VW Group TSI Timing Chain Rattle — Why a Cold-Start Rattle Should Never Be Ignored
A metallic rattle for the first few seconds after start-up on a VW Group 1.8/2.0 TSI is the classic symptom of a worn timing chain tensioner — a routine repair if caught early, an engine-ending fault if ignored.
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VW GROUP DIAGNOSTICS & REPAIRS // 2026-10-28 // 2 min read
VW Group 2.0 TDI EGR Cooler Faults — The Coolant Loss That Isn't a Head Gasket
Unexplained coolant loss on a VW Group 2.0 TDI is very often a cracked EGR cooler — a fault that mimics a head gasket failure but costs a fraction to repair. Here's what to look for.
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VW GROUP DIAGNOSTICS & REPAIRS // 2026-10-28 // 2 min read
DSG Gearbox Warning Light — Limp Mode, Judder and Mechatronic Faults Explained
A DSG warning on your VW, Audi, Škoda or SEAT — limp mode, harsh shifts or judder — usually points to the mechatronic unit or clutch pack, not a whole gearbox. Here's what the messages mean and how the faults are diagnosed.
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VW GROUP WARNING LIGHTS // 2026-10-28 // 2 min read
VW Group AdBlue Faults — Countdown Warnings, NOx Sensors and Crystallisation
A countdown to "no engine start" on your VW, Audi, Škoda or SEAT diesel is legally enforced — but if the warnings persist with a full tank, you likely have a sensor, NOx sensor or crystallisation fault. Here's how the system works and how we diagnose it.
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VW GROUP WARNING LIGHTS // 2026-10-28 // 3 min read
VW Group DPF Warning Light — What It Means and When to Act
A DPF warning lamp on your VW, Audi, Škoda or SEAT usually means the filter needs a regeneration, not a replacement. Here's what the light means, when it's safe to drive, and when it needs professional attention.
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VW GROUP DIAGNOSTICS & REPAIRS // 2026-10-28 // 2 min read
CAN Bus Faults on VW Group Cars — Multiple Warnings, One Cause
Multiple unrelated warnings, intermittent electrics or battery drain on a VW Group car usually mean a CAN data bus fault — and the unit that logged the error is rarely the one that's broken. Here's how these faults are found.
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VW GROUP MAINTENANCE // 2026-10-28 // 2 min read
VW Group Start-Stop Not Working — Battery Health, AGM and Registration Explained
When start-stop goes quiet on your VW, Audi, Škoda or SEAT, the car has usually disabled it to protect a tired battery — and a replacement must be the right type and properly registered. Here's how the system works.
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