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How to enable Boost Tub/Pressure using PIWIS III

DIY PIWIS III guide for enabling the Cayenne E3 instrument cluster Boost Pressure display, with supported coding paths, power cautions, and admin verification notes.

General Published May 26, 2026

How to Enable Boost Tub/Pressure Using PIWIS III

Scope

This guide covers enabling the Boost Pressure / boost tube display in the instrument cluster on a 2019 Porsche Cayenne 9Y0/9YA/E3. The strongest source uses the label Boost Pressure and says PIWIS may show the cluster as Kombi; the admin should verify whether the final site title should say Boost Tube, Boost Tub, or Boost Pressure. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-27.html#post19038681

This coding is for the display/gauge, not for increasing engine boost or tuning the vehicle. Forum evidence describes the change as a boost gauge scale/readout/display change, not a PIWIS tuning function. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-8.html#post17195937

Known Fitment / Evidence Limits

The best documented successful setup was reported on a 2019 Cayenne S without Sport Chrono, where the author enabled both the boost tube at the bottom of the instrument-cluster gauge and Boost Pressure in the custom 4-line display. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-11.html#post17262645

Admin verification is still needed for other trims, engines, software levels, and E-Hybrid models. One 2019 Cayenne E-Hybrid owner reported the coded boost gauge pegging at maximum / 20 psi, and another user was unsure whether the Hybrid displays boost accurately. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-37.html#post20043689 https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-37.html#post20043715

Tools and Supplies

Warnings Before Coding

Procedure

1. Prepare the Vehicle

  1. Park safely, set the parking brake, and leave the vehicle stationary.
  2. Connect external battery support using the vehicle-approved jump/emergency-start points or the connection method verified from the owner's manual/service information. Forum guidance says to connect the power supply to the engine-bay leads, with the process described in the vehicle manual. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-6.html#post17145597
  3. Connect PIWIS III to the vehicle.
  4. Switch ignition on without starting the engine. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-12.html#post17389186

2. Open Instrument Cluster / KOMBI Coding

  1. In PIWIS III, open the control-unit overview.
  2. Select Kombi if PIWIS uses the German module name, or Instrument Cluster if the English label is shown. The direct boost-pressure source says PIWIS may show the instrument cluster as Kombi. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-27.html#post19038681
  3. Open Coding.
  4. Choose manual coding without rules. The source specifically suggests selecting Kombi and using manual coding without rules for the Boost Pressure path. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-27.html#post19038681

3. Set the Boost Pressure Custom Display Line

Navigate to:

Instrument Cluster / Kombi → Factory setting → Factory setting → individual options line 1 → Boost Pressure

Set individual options line 1 to Boost Pressure. This exact target path is directly cited for the Boost Pressure display. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-27.html#post19038681

Only line 1 is confirmed by the source. The author speculated that lines 2, 3, or 4 might work, but that needs admin verification before publishing as an option. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-11.html#post17262645

4. Enable the Related Boost Display Items

The successful 2019 Cayenne S report lists these related instrument-cluster settings. These were documented from Launch/x431-style menus and described as Launch/PIWIS-relevant, so the admin should verify the exact PIWIS wording before final publication. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-11.html#post17262645

Set or verify the following where present:

The same source also listed these settings, but their necessity is less clear and should be admin-verified before treating them as required:

Do not change Max boost pressure normal unless the admin has a verified reason. The source reports 1.4 Bar as the default and says it was not changed. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-11.html#post17262645

5. Write / Save the Coding

Use PIWIS to write or save the changed coding for the Kombi / Instrument Cluster module. PIWIS examples elsewhere in the thread use the pattern Overview → target control unit → Coding / Coding manual → Kodierwert → change value → write/save coding, but those examples were for other functions, so the exact PIWIS save prompt for this boost display needs admin verification. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-40.html#post20552659

After saving, read faults and clear any coding-session faults if appropriate. Forum users commonly advise reading and deleting errors after PIWIS coding. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-2.html#post17122196

6. Refresh the Cluster Custom Display

If Boost Pressure does not appear immediately in the custom 4-line display, use the steering-wheel controls to switch the cluster view from Customized to Vehicle, then back from Vehicle to Customized. The source says PCM custom settings alone did not reliably make Boost Pressure “stick,” and this cluster-view toggle was used after setting individual options line 1 to Boost Pressure. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-11.html#post17262645

Verification Checks

  1. Confirm the right-side instrument-cluster gauge/tube can show Boost Pressure instead of the coolant tube/bar graph. The source describes enabling the boost tube at the bottom of the instrument-cluster gauge. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-11.html#post17262645
  2. Confirm Boost Pressure appears as the selected item in the custom 4-line display after toggling the cluster view from Customized to Vehicle and back. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-11.html#post17262645
  3. Scan all modules for faults and clear only appropriate coding-session faults. Users report clearing faults after coding, and one user reported clearing all faults removed a check-engine light after coding work. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-13.html#post17390115
  4. If the display pegs at maximum boost or does not change normally, stop and document the vehicle trim, engine, PIWIS version, and exact changed values. A 2019 Cayenne E-Hybrid owner reported a full-scale / 20 psi display after coding, and the cause was not resolved in the supplied evidence. https://rennlist.com/forums/cayenne-9y0-2019/1224875-coding-cayenne-e3-37.html#post20043689

Troubleshooting Notes

Admin Verification Required Before Publishing