P0087 means A4 rail pressure fell below target. Audi TSB 01-13-31 identifies a narrow 2013–2014 2.0 TFSI CPMA/CPMB case: extended idle or stop-and-go with A/C off can heat the rail, with freeze-frame coolant temperature above 102°C supporting the condition, and calibration applicability determines an update. Otherwise measure low-side supply and requested/actual high pressure under load before replacing pumps.
Match the symptom
Select the closest observation. The result changes the first test; it does not name a part to replace.
Save low/high pressure during crank.
What can set P0087—and how to separate it
The order below is evidence-driven, not a universal probability ranking. Vehicle year, repair history, companion codes and the operating condition in freeze frame change where diagnosis should begin.
| Possible cause | Evidence that supports it | First useful test |
|---|---|---|
| Weak in-tank pump, filter or supply restriction | Mechanical low-side pressure/volume fails | Low-side gauge and volume test |
| High-pressure pump or control valve fault | Low side passes but rail misses command | Commanded/actual rail test |
| Leaking injector or rail pressure loss | Residual/balance/leak evidence | Residual and injector test |
| Pressure sensor or wiring bias | Mechanical/known-good comparison disagrees | Sensor plausibility and circuit test |
| TDI contamination or high-pressure system damage | Fuel quality/debris and diesel procedure | Engine-specific TDI inspection |
Read freeze frame for the hot-fuel signature
Look for long idle/stop-and-go, A/C-off operation and coolant temperature over 102°C on an eligible 2013–2014 car. Confirm ECM software before using the bulletin.
A different year or engine requires normal pressure diagnosis even if the weather was hot.
Separate low-side supply from rail generation
Measure tank-pump pressure/volume and voltage under demand while graphing specified versus actual rail pressure. Idle readings can miss a load failure.
Test controller output, restriction, residual pressure, high-pressure pump and regulating valve by erWin before assigning parts.
Verify the same heat/load condition
After an applicable software update or physical repair, repeat the safe condition and confirm rail pressure follows request.
Normal performance, stable trims and no pending P0087 complete the repair check.
Save these scan-data clues
Freeze frame is a snapshot of conditions when the PCM matured the fault. It can distinguish an idle-only problem from a load, cold-start or monitor-completion problem. Clearing first throws that context away.
- Exact VIN, platform, model year and engine sales code
- All confirmed, pending and permanent companion codes
- RPM, load, coolant temperature and vehicle speed
- Relevant commanded and actual scan data
- Recent service, repairs and symptom conditions
- Manufacturer bulletin and current software/VIN status
A practical diagnostic workflow
- 01Identify gasoline TSI versus TDI system
Pressure stages and hazards differ.
- 02Save requested/actual pressure and companions
Record crank, idle and load.
- 03Inspect for leaks and fuel contamination
Stop for visible leakage.
- 04Measure low-side pressure correctly
Do not trust invalid scan channels.
- 05Test rail pressure and control
Use protected high-pressure methods.
- 06Localize residual loss and injector contribution
Follow engine-specific procedure.
- 07Verify crank and load pressure
Confirm no pending P0087.
Do not replace the most commonly named component from P0087 alone. Confirm the exact engine, preserve evidence and complete the manufacturer test sequence before ordering parts.
Why the model year changes the test
Audi A4 diagnostics cross longitudinal B6, B7, B8/B8.5, B9 and newer platforms with naturally aspirated, TFSI and market-specific TDI engines. Longitudinal packaging does not make a transverse VW procedure interchangeable. Confirm VIN, model year, engine code, emissions configuration, transmission and current software before using a component map or bulletin.
- The hot-fuel bulletin is limited to 2013–2014 CPMA/CPMB 2.0 TFSI calibration groups.
- Coolant temperature above 102°C is supporting evidence, not a universal threshold for every A4.
- Software cannot repair voltage loss, restriction, contamination or pump wear.
- Direct-injection fuel remains hazardous after shutdown.
P0087 FAQ
Does P0087 mean the high-pressure pump is bad?+
No. Low-side supply, filter, injector leakage, sensor bias and control faults can all reduce rail pressure.
Can I drive?+
Avoid driving because power can drop or the engine can stall.
Can a clogged filter cause it?+
Yes on systems with a serviceable or integrated filter restriction.
Is TDI diagnosis the same as TSI?+
No. Diesel high-pressure contamination and safety procedures differ.
Can scan data be misleading?+
Yes. Some VW TSI applications expose a non-valid low-pressure channel, requiring a mechanical gauge.
Should I loosen a rail line to test fuel?+
No. High-pressure fuel can penetrate skin and cause serious injury.
Can P0300 relate?+
Yes. Shared pressure loss can misfire several cylinders.
What confirms repair?+
Requested and actual pressure remain correct during crank and load with no pending P0087.
Ford diagnostic references
These documents explain Ford monitor operation. Exact pinpoint tests, connector views and specifications must be selected for the truck's VIN and model year in current service information.
01Audi TSB 01-13-31 — A4 P0087 hot-fuel branch2013–2014 A4 2.0 TFSI CPMA/CPMB software branch for extreme heat/idle conditions and coolant temperature above 102°C evidence↗02Audi erWin service informationOfficial VIN-, engine-code- and model-year-specific repair information↗03Audi owners and manualsOfficial vehicle support and owner information↗