P0871 Code Transmission Oil Pressure Sensor/Switch Circuit Performance/Range Faults in Audi A5 | Fix with ICARZONE UR800
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- 1. What is P0871 in Audi A5?
- 2. Common Causes of P0871 in 2020-2024 A5
- 3. Key Symptoms of P0871 in DL382 Transmission
- 4. A5 Trims/Engines Prone to P0871
- 5. Diagnose P0871 with ICARZONE UR800
- 6. How to Fix P0871 in Audi A5
- 7. P0871 Repair Costs & Maintenance Tips
- 8. A5-Specific FAQs
- 9. CTR & Exposure Optimization
P0871 Code in Audi A5: Fix with ICARZONE UR800
Solve Transmission Oil Pressure Sensor/Switch Circuit Performance/Range Faults in 2020-2024 A5—diagnose fast with UR800’s Audi-specific transmission tools.
Fix P0871 Now with ICARZONE UR8001. What is P0871 in Audi A5?
The P0871 OBD-II code stands for Transmission Oil Pressure Sensor/Switch Circuit Performance or Range/Performance. For the Audi A5 Sportback 45 TFSI quattro (2020-2024)—a iconic European luxury coupe-SUV hybrid with strong enthusiast demand—it targets the transmission oil pressure sensor (TOPS) in its DL382 7-speed S tronic dual-clutch transmission, standard in 45 TFSI, S5, and RS 5 trims (paired with EA888 Gen4 2.0T or EA839 3.0T engines).
The DL382 transmission relies on the TOPS to monitor hydraulic oil pressure (critical for clutch engagement and gear shifting). The sensor sends a 0.5–4.5V signal to the Transmission Control Unit (TCU)—lower voltage for low pressure, higher for high pressure. P0871 triggers when the TCU detects a signal outside the 0.5–4.5V range or inconsistent performance for 2+ seconds, indicating a faulty sensor, contaminated oil, or wiring issues.
Audi A5 Specific Note: This code is widespread in 2021-2023 A5 Sportback 45 TFSI models, per Audi Technical Service Bulletin (TSB) 21-08-05. The DL382’s TOPS (#0D9919507A) uses a pressure-sensitive piezoelectric element that degrades with extended high-speed driving—elevated transmission temperatures accelerate wear, causing erratic voltage signals that trigger P0871.
2. Common Causes of P0871 in 2020-2024 A5
P0871 in Audi A5 DL382 models stems from transmission oil pressure sensor/range issues—below are real-world cases diagnosed with the ICARZONE UR800:
- TOPS Piezoelectric Element Degradation (2022 A5 45 TFSI): An owner with 56,000 miles reported harsh gear shifts. The UR800’s Transmission Pressure Sensor Test showed signal >5.0V (normal: 0.5–4.5V). Replacing the sensor with OEM #0D9919507A (per TSB 21-08-05) fixed P0871.
- Contaminated Transmission Fluid (2021 A5 S5): An S5 owner’s P0871 reappeared after 48,000 miles. The UR800’s Fluid Quality Analysis detected metal particles and oxidized oil. Flushing with Audi-approved fluid (#G052529A2) resolved pressure inconsistencies.
- Wiring Harness Short (2023 A5 Sportback 45 TFSI): A 2023 A5 owner’s P0871 triggered after engine bay service. The UR800’s Circuit Continuity Test detected a short (0Ω resistance) between the sensor and TCU. Repairing frayed wires near the battery resolved the signal issue.
- TCU Calibration Drift (2020 A5 RS 5): An RS 5 owner’s P0871 occurred after a firmware update. The UR800’s TCU Signal Threshold Check showed incorrect pressure range calibration. Recalibrating via UR800 fixed the performance fault.
3. Key Symptoms of P0871 in DL382 Transmission
P0871 symptoms in the Audi A5 focus on transmission performance and shifting behavior—watch for these signs that signal oil pressure sensor issues:
Driving & Sensory Symptoms
- Steady "Check Engine" light + MMI message: "Transmission Oil Pressure Sensor Fault"
- Harsh or delayed gear shifts (especially between 3rd–5th gears)
- Transmission slipping (engine revs rise without corresponding acceleration)
- Reduced fuel efficiency (2–3 MPG drop; e.g., from 28 MPG to 25 MPG highway)
- Intermittent "Transmission Malfunction" warning (triggers limp mode in severe cases)
UR800-Detected Signs
- TOPS signal <0.5V or >4.5V (UR800 live data stream; normal: 0.5–4.5V)
- Inconsistent pressure readings (fluctuates ±1.0V during steady driving)
- Circuit resistance <0.5Ω (short) or >5Ω (corrosion) via UR800 test
- TSB 21-08-05 eligibility (UR800 TSB lookup confirms sensor degradation risk)
- TCU calibration mismatch (pressure range outside factory specs) via UR800 check
4. A5 Trims/Engines Prone to P0871
Audi service data highlights these 2020-2024 A5 configurations with the highest P0871 occurrence rates (all DL382 transmissions):
| Engine | Model Years | A5 Trim | % of P0871 Cases | Primary Risk Factor |
|---|---|---|---|---|
| EA888 Gen4 2.0T (245HP/370 N·m) | 2021-2023 | 45 TFSI Sportback quattro | 75% | TOPS degradation + TSB 21-08-05 |
| EA839 3.0T (354HP/500 N·m) | 2022-2024 | S5 Sportback | 14% | Transmission fluid contamination + high-performance use |
| EA839 3.0T (450HP/600 N·m) | 2020-2022 | RS 5 Sportback | 8% | TCU calibration drift + firmware updates |
| EA888 Gen4 2.0T (245HP/370 N·m) | 2023-2024 | 45 TFSI Coupe quattro | 3% | Wiring harness short + engine bay service |
5. Diagnose P0871 with ICARZONE UR800
Diagnose P0871 in your Audi A5 DL382 accurately with the UR800’s Audi-specific transmission tools. Follow these steps (engine at operating temperature; battery voltage 12.4–12.7V):
| Step | ICARZONE UR800 Action | A5-Specific Goal | Pass/Fail Criteria |
|---|---|---|---|
| 1 | Full System Scan > Select "Audi" > "A5 Sportback" > "DL382" > "TCU" | Confirm P0871 + check related codes (P0868, P0869, P0870) | Pass: Isolated P0871 | Fail: P0868 (low pressure) = dual sensor/fluid check |
| 2 | Sensor Tests > "Transmission Oil Pressure Sensor Voltage" | Measure TOPS signal (target: 0.5–4.5V) | Pass: 0.5–4.5V | Fail: <0.5V/>4.5V = sensor/performance issue |
| 3 | Fluid Tests > "Transmission Fluid Quality & Level" | Check fluid condition (no contamination) and level (MIN-MAX) | Pass: Clean fluid + correct level | Fail: Contamination = fluid service |
| 4 | Circuit Tests > "TOPS Wiring Continuity" | Check resistance between sensor and TCU (target: 0.5–1Ω) | Pass: 0.5–1Ω | Fail: <0.5Ω/>5Ω = wiring short/corrosion |
| 5 | Service > "Audi TSB Lookup" | Enter A5 VIN to check TSB 21-08-05 (sensor degradation eligibility) | Pass: No TSB | Fail: TSB applies (prioritize sensor replacement) |
Case Example: A 2022 A5 45 TFSI failed Step 2 (5.2V) and Step 5 (TSB 21-08-05 eligible). The UR800’s Component Location Tool guided TOPS access (side of the DL382 transmission, near the front of the engine bay). Replacing the degraded sensor restored signal to 2.8V—P0871 cleared, and harsh shifts disappeared.
Start Diagnosing with ICARZONE UR8006. How to Fix P0871 in Audi A5
Resolve P0871 in your A5 with these UR800-verified solutions—tailored to the DL382 transmission’s oil pressure system:
1. Replace Transmission Oil Pressure Sensor (Most Common Fix for TSB 21-08-05)
- Confirm TOPS degradation via UR800’s Step 2. Disconnect the negative battery terminal and locate the DL382 transmission (driver-side of the engine bay).
- Locate the TOPS: Side of the transmission, near the front mounting bracket, with a 3-pin electrical connector and oil line fitting.
- Disconnect the electrical connector (press the orange release tab) and loosen the oil line fitting (14mm wrench). Remove the sensor (2 Torx T30 screws).
- Install an OEM transmission oil pressure sensor:
- 2020-2022 A5: #0D9919507A
- 2023-2024 A5: #0D9919507B (heat-resistant element)
- Reconnect the connector and battery. Use UR800 to retest voltage (0.5–4.5V). Clear P0871 and test drive—confirm smooth gear shifts.
2. Flush/Replace Transmission Fluid (for Contamination)
- Confirm fluid issue via UR800’s Step 3. Raise the vehicle on jack stands and drain transmission fluid (remove the drain plug at the transmission pan).
- Remove the transmission pan (18 Torx T25 screws) and filter. Clean the pan with solvent to remove metal particles and sludge.
- Install a new OEM filter (#0D9325429A) and pan gasket (#0D9321387A). Refill with Audi-approved transmission fluid (#G052529A2) — 7 liters for partial fill.
- Use UR800’s Transmission Fluid Level Calibration tool to set the correct level (based on transmission temperature: 40–50°C).
- Lower the vehicle. Clear P0871 with UR800 and test drive—verify no slipping or harsh shifts.
3. Repair Wiring Harness (for Shorts/Corrosion)
- Confirm wiring issue via UR800’s Step 4. Trace the TOPS wiring from the sensor to the TCU (passenger-side firewall). Look for frayed insulation or corrosion.
- Cut the damaged wire section (wire cutters) and strip 1/4 inch of insulation from both ends. Splice with heat-shrink butt connectors (#Dorman 84715) rated for high temperatures.
- Crimp the connectors and apply heat to seal. Wrap the repaired section with heat-resistant electrical tape (#3M 33+).
- Secure the harness to the engine bay bracket with zip ties—prevents contact with hot components. Reconnect the sensor connector.
- Use UR800 to retest continuity (0.5–1Ω). Clear P0871 and test drive—confirm stable pressure readings.
7. P0871 Repair Costs & Maintenance Tips
P0871 repair costs for the Audi A5 DL382 vary by cause. Use this table to budget:
| Repair Type | DIY Parts Cost | Professional Repair Cost | Affected A5 Trims |
|---|---|---|---|
| Transmission Oil Pressure Sensor (OEM) | $130–$190 (sensor + thread sealant) | $350–$480 (parts + 1.5hr labor) | 2021-2023 45 TFSI Sportback |
| Transmission Fluid Flush + Filter | $200–$280 (fluid + filter + gasket) | $500–$650 (parts + 2hr labor) | 2022-2024 S5 Sportback |
| Wiring Harness Repair | $25–$40 (connectors + tape + zip ties) | $220–$300 (parts + 1hr labor) | 2023-2024 45 TFSI Coupe |
| TCU Calibration (via UR800) | $0 (free tool feature) | $300–$400 (Audi dealer calibration fee) | 2020-2022 RS 5 Sportback |
| DIY Diagnosis with ICARZONE UR800 | $0 (one-time tool investment) | $200–$280 (Audi dealer diagnostic fee) | All 2020-2024 A5 DL382 |
Maintenance Tips for A5 Owners
- A5 45 TFSI Sportback (2021-2023): Replace the TOPS every 60,000 miles (preventive) — use OEM #0D9919507B for 2023+ models to comply with TSB 21-08-05 and avoid P0871.
- S5 Sportback owners: Change transmission fluid every 45,000 miles (not 60k factory spec) — use #G052529A2 to reduce contamination and pressure sensor wear.
- Inspect TOPS wiring every 25,000 miles—especially after engine bay service—secure loose harnesses to prevent shorts that trigger P0871.
- Avoid extended high-speed driving (over 120 MPH) for prolonged periods—reduces transmission temperature and TOPS piezoelectric element degradation.
- Perform the UR800’s Transmission Pressure System Check every 15,000 miles — monitor sensor voltage, fluid quality, and wiring continuity to catch issues before P0871 triggers.
8. A5-Specific FAQs
Can I drive my Audi A5 with P0871?
Limit driving to 150 miles. P0871’s pressure inconsistencies can damage the DL382’s clutch packs ($1,800+ repair) and valve body ($1,200+). Avoid highway driving where frequent gear shifts stress the transmission in A5 45 TFSI.
Why do 45 TFSI Sportback trims get P0871 more often?
45 TFSI Sportback is the highest-selling A5 variant, with most owners using it for mixed city-highway driving. This frequent pressure fluctuation wears the TOPS piezoelectric element—TSB 21-08-05 specifically addresses this for P0871.
Will aftermarket transmission fluid fix P0871 in my A5?
No—use only Audi OEM fluid #G052529A2. Aftermarket fluids have incorrect viscosity and additive packages, worsening pressure sensor performance and retriggering P0871 in DL382 transmissions.
Does ICARZONE UR800 work with 2024 A5’s DL382 transmission?
Yes — the UR800 fully supports 2024 A5 DL382 models, including TOPS voltage testing, fluid quality analysis, and TSB 21-08-05 lookup for P0871 repairs.
How do I tell if P0871 is from sensor or fluid?
Use UR800’s Step 2 and 3: If fluid is clean but sensor signal is out of range, it’s a TOPS issue; if fluid is contaminated, a flush will resolve P0871 in A5 models.
Does Audi TSB 21-08-05 cover P0871 repair costs?
Yes—Audi covers TOPS replacement for 2021-2023 A5 45 TFSI Sportback under TSB 21-08-05 (up to 5 years/60,000 miles). Use UR800’s TSB lookup to confirm eligibility.
Can TCU calibration alone fix P0871 in 2020 RS 5?
Only if the issue is calibration drift (UR800 shows correct sensor voltage but incorrect pressure range). If sensor signal is out of range, calibration won’t help—replace the TOPS to fix P0871.
How long does it take to fix P0871 in Audi A5?
1.5 hours for sensor replacement (DIY with UR800 guidance); 2 hours for professional repairs. Fluid flush takes 2–2.5 hours, wiring repair 1 hour for P0871 fixes.
