BENTLEY GENUINE TOOL - ASE40110072000 - PRESSURE SENSOR VAG1397B

The VAG 1397B is the genuine Volkswagen Group digital pressure sensor. It measures from -1 to 3 bar and sends the reading to the diagnostic tester rather than to a dial, so the value is logged against the vehicle. Two jobs dominate its use: charge pressure on turbocharged engines, and leak-tightness testing on cooling systems.

What it measures, and where the reading goes

The measuring range is -1 to 3 bar, and the display switches between PSI, mbar, kPa and mPas — so the same sensor reads a boost figure a US technician expects and a European workshop manual value without conversion.

The important part is the analogue output. The VAG 1397B is a sensor, not a standalone gauge: it feeds the measured value to the diagnostic tester, which displays it. That means the reading lands inside the diagnostic session alongside everything else recorded for that vehicle, instead of being a number someone reads off a dial and writes down.

Charge pressure on turbocharged engines

The classic application. Actual charge pressure is compared against the specified value for the engine, and the gap between them is what separates a wastegate fault from a leaking charge-air path from a sensor reporting badly.

Because the value reaches the tester rather than a gauge, actual and specified can be compared on one screen while the engine is under load — which is where a boost fault usually appears and a static test usually misses it.

Cooling system leak-tightness, including high-voltage battery circuits

The second application is checking a cooling system holds pressure. On a combustion engine that is routine diagnostics.

On a high-voltage vehicle it is a safety test. Used together with the cooling system tester for high-voltage batteries, VAS 691 005, the VAG 1397B performs leak testing on the high-voltage battery cooling circuit. A battery pack cooled by a circuit that does not hold pressure is a pack heading toward a thermal event on a timeline nobody controls — and coolant inside a high-voltage enclosure is its own fault path.

This is the test that says whether a pack's thermal management is intact after a collision, a coolant service, or a pack reseal.

VAG 1397B and VAG 1397A are not the same tool

VAG 1397A (ASE40110000000) is the older turbocharger tester kit — an analogue gauge assembly for reading boost pressure directly.

VAG 1397B (ASE40110072000) is the digital pressure sensor that outputs to the diagnostic tester. It is the current tool, and it is the one specified where the procedure expects the value to appear in the tester rather than on a dial.

If a workshop manual calls for the reading to be displayed on the diagnostic tester, the A kit will not satisfy the procedure. Check which the procedure names before ordering.

What you need alongside it

The sensor connects through vehicle- and system-specific adapters, and for high-voltage battery cooling work it is used with VAS 691 005 and its adapter sets, which carry their own ASE numbers and are ordered separately.

Tell us which systems you intend to test — turbo charge pressure, conventional cooling, high-voltage battery cooling, or all three — and we will list the adapters that combination requires. A sensor without the right adapter cannot connect to the vehicle.

Specification

Availability

Genuine VAG special tool, shipped from the USA, sourced to order.

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