Checking turbocharger and charge pressure regulating valve - engine codes AEB, AJL — AUDI

🧭 Before you start

Fits: Audi A4 B5 (8D)

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• If the self-diagnosis function of the engine control unit detects a fault in the charge pressure control system, the duty cycle in display zone (4) is set to 5% (constant).

🔧 Engine codes this applies to

📋 Procedure

1. Connect T-piece with hose of turbocharger testerV.A.G 1397A to intake manifold (front).
2. Route test hose under rear edge of bonnet and through right window into passenger compartment.
3. Switch on turbocharger tester and set measuring range selector switch to position (I) (absolute pressure).
4. Fit test hose to connection (I). [Note: Hose connections must be completely airtight, otherwise measurement errors may occur.Take care not to trap test hose at bonnet and side window.Pressing memory button (M) on turbocharger tester causes last measured value to be stored until memory button (M) is pressed again or tester is switched off.The decimal point in the display flashes to indicate that the value is being stored.If the battery voltage of the turbocharger tester drops below the minimum level, an arrow will appear at the top left of the display.Before performing the test, drive vehicle moderately fast for at least 3 km (choose a route where traffic lights etc. will not hold you up).]
5. ⚠ Accidents can be caused if the driver is distracted by test equipment while road-testing, or if test equipment is not properly secured.Observe safety precautions . — Accelerate vehicle in 3rd gear (or position 2) from 2000 rpm at full throttle while a second mechanic observes the rev counter.

6. Second mechanic should press memory button (M) on V.A.G 1397A at approx. 3000 rpm.
7. Accelerate vehicle in 3rd gear (or position 2) from 2000 rpm at full throttle while a second mechanic observes the rev counter.
8. Second mechanic should press memory button (M) on V.A.G 1397A at approx. 2500 rpm. [Note: On vehicles with automatic gearbox the charge pressure test is not always a reliable indication of the proper function of the charge pressure control system. Therefore, if the pressure value is close to the lower tolerance limit, check the load signal in order to test the charge pressure control function.]
9. ⚠ Accidents can be caused if the driver is distracted by test equipment while road-testing, or if test equipment is not properly secured.Observe safety precautions . — From menu (1), select diagnostic function "“Measured values”" and press → key to continue.
10. Press keys 25 on keypad (1) to select "“Display group 025”" and confirm entry by pressing Q key.
11. Accelerate vehicle at a constant rate and check display in display zones (2) and (3). [Note: If the self-diagnosis function of the engine control unit detects a fault in the charge pressure control system, the duty cycle in display zone (4) is set to 5% (constant).]

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