Digital Pressure Readings for Gasoline Direct-Injection Fuel Systems
The AUTOOL PT640 reads high-pressure fuel at a GDI test point up to 360 bar and shows current, maximum, minimum and differential pressure together, so there is no mechanical needle to interpret. It is for gasoline direct injection only, not diesel common rail.
- 0–360 bar
- 1% FS Accuracy
- Current / Max / Min / Differential
- bar · kg/cm² · psi
- GDI Hose and Fitting Set
Key Features
-
High-Pressure GDI Range
Covers direct-injection fuel pump pressure, with an overload alarm before the sensor limit is reached.
-
Four Readings on One Screen
The backlit display shows real-time, maximum, minimum and differential pressure plus measurement time, and stays readable in low light.
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Unit Switching
One button switches between bar, kg/cm² and psi to match the service data you are working from.
-
Data Lock and Zeroing
Lock the reading and screen for stable observation, then clear and zero before or after a measurement.
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Fittings for the Fuel Line
Adapter hoses, metal adapters and a T-fitting connect the probe to the direct-injection fuel line.
What’s in the Box
- PT640 GDI fuel pressure gauge with probe hose
- Adapter hoses
- Metal adapters
- T connector
- Carrying case
- User manual

How to Use
- Release fuel pressureRemove the fuel pump fuse, relay or pump plug, run the engine until it stalls, crank it 2-3 more times, then disconnect the negative battery terminal.
- Fit the batteriesOpen the rear cover and install the AAA batteries by the polarity marks.
- Choose the adapterSelect the adapter for the vehicle and attach it to the measuring probe.
- Connect to the GDI lineAfter depressurizing per the vehicle procedure, install only the verified GDI-rated hose and adapter.
- Zero and measureLong-press to power on, long-press to zero, select the unit and start measuring.
Unit selection, adapter setup and troubleshooting: PT640 user manual (PDF).
Good to Know
Caution
- Do not connect the PT640 to a diesel common-rail system.
- GDI fuel pressure is high-energy: always depressurize before connecting, and use an adapter that seals properly to avoid leaks and false readings.
Care
- Place a towel or cloth under the connection when removing the fuel pipe so fuel does not reach the ground.
- Store the gauge dry when not in use.




































