P0155 Code in Ford F-150: Fix Bank 2 Sensor 1 Heater with ICARZONE MA900
P0155 Code in Ford F-150: Fix with ICARZONE MA900
Solve Bank 2 Sensor 1 oxygen sensor heater issues in 2015-2023 F-150. Diagnose & repair with MA900’s Ford-specific tools.
Fix P0155 with MA900 Now1. What is P0155 in Ford F-150?
P0155 is an OBD-II Diagnostic Trouble Code defined as Oxygen Sensor Heater Circuit Malfunction (Bank 2, Sensor 1). For the Ford F-150—America’s best-selling pickup for 46 years—this code targets the upstream oxygen sensor’s heater element (mounted before the catalytic converter on Bank 2) critical for fast sensor warm-up.
F-150’s 3.5L EcoBoost, 5.0L V8, and 2.7L EcoBoost engines rely on this heater to bring the O2 sensor to operating temperature (600°F+) in 30–60 seconds. P0155 triggers when the Engine Control Module (ECM) detects a heater circuit issue—either open, shorted, or with insufficient current. This is especially common in 2015-2020 F-150s, as noted in Ford Technical Service Bulletin (TSB) 18-2349.
2. Common Causes in 2015-2023 F-150 Models
Failed O2 Sensor Heater (2018 F-150 XLT 3.5L EcoBoost): A 2018 XLT owner with 72,000 miles noticed a Check Engine Light. MA900’s O2 Sensor Heater Test showed 0Ω resistance (normal: 10–15Ω), confirming heater failure. The 3.5L’s high exhaust temps degraded the element—replacing with OEM sensor #BL3Z-9F472-A fixed the issue.Wiring Harness Short (2017 F-150 Lariat 5.0L V8): A 2017 Lariat owner’s P0155 appeared after off-roading. MA900’s Circuit Continuity Test found a short between the sensor wire and frame rail. Engine vibration had worn through insulation—repairing with heat-resistant wiring (per TSB 18-2349) resolved it.Blown Fuse (2020 F-150 XL 2.7L EcoBoost): A 2020 XL owner’s P0155 was intermittent. MA900’s Fuse Panel Test identified a blown 15A O2 heater fuse (Fuse #37 in the engine bay box). The 2.7L’s heater circuit had a temporary surge—replacing the fuse and inspecting for shorts fixed it.Corroded Connector (2016 F-150 Platinum 3.5L EcoBoost): A 2016 Platinum owner in the Rust Belt had P0155. MA900’s Connection Resistance Test showed 22Ω (normal: <0.5Ω) at the sensor plug. Road salt had corroded terminals—cleaning with contact cleaner and applying dielectric grease restored function.
3. Key Symptoms in Ford F-150
Performance & Efficiency
- Steady Check Engine Light (not flashing)
- Delayed engine warm-up in cold weather
- Fuel economy drop (1–3 MPG in 3.5L EcoBoost)
- Rough idle until engine reaches operating temp
- Reduced towing power (common in 5.0L V8)
System-Specific Signs
- Oxygen sensor takes >2 minutes to reach operating temp (via MA900)
- Failed emissions tests (due to slow sensor response)
- 2018+ F-150s: "Exhaust System Fault" dash message
- Symptoms worsening in sub-40°F (4°C) weather
- 3.5L EcoBoost: Intermittent turbo lag on cold starts
4. F-150 Engines/Trims Prone to P0155
Engine Model Years F-150 Trims % of P0155 Cases Primary Risk Factor 3.5L EcoBoost V6 (GTDI) 2015–2020 XLT, Lariat, Platinum 48% High exhaust temps damaging heater elements (TSB 18-2349) 5.0L Coyote V8 2015–2023 XL, XLT, Raptor 32% Wiring wear from engine vibration 2.7L EcoBoost V6 2018–2023 XL, XLT, King Ranch 15% Heater circuit fuse surges 3.5L PowerBoost Hybrid 2021–2023 Lariat, Platinum, Limited 5% Early ECM calibration issues (TSB 21-1442)
5. Diagnostic Steps with ICARZONE MA900
Diagnose P0155 in your F-150 accurately with MA900’s Ford-specific tools—follow these steps:
| Step | Action with MA900 | F-150-Specific Goal | Pass/Fail Criteria |
|---|---|---|---|
| 1 | Full System Scan > Select "Ford" > "F-150" > "Engine Control Module" | Confirm P0155 + check for related codes (P0154, P0156, P0157) | Pass: Isolated P0155 | Fail: Multiple heater circuit codes |
| 2 | Sensor Tests > "O2 Sensor Heater Test" | Measure Bank 2 Sensor 1 heater resistance (F-150: test cold engine) | Pass: 10–15Ω resistance | Fail: 0Ω (short) or ∞Ω (open) |
| 3 | Electrical Tests > "Circuit Voltage Test" | Check 12V power to sensor (F-150: fuse #37 in engine bay) | Pass: 11.5–12.5V at sensor connector | Fail: <10V (fuse/battery issue) |
| 4 | Live Data > "Sensor Warm-Up Monitor" | Track time to 600°F (315°C) (F-150: target <60 seconds) | Pass: Reaches temp in 30–60s | Fail: >90s (heater failure) |
| 5 | Service Functions > "Ford TSB Lookup" | Enter F-150’s VIN to check TSB 18-2349 (2015-2020) or 21-1442 (2021+) | Pass: No relevant TSB | Fail: TSB applies (follow Ford’s fix) |
Case Example: A 2019 F-150 3.5L EcoBoost failed Step 2 (∞Ω resistance) and Step 3 (12V power present). MA900’s Component Location tool showed Bank 2 Sensor 1 near the passenger-side exhaust manifold. Replacing the OEM sensor (#BL3Z-9F472-A) and clearing codes with MA900 fixed P0155—verified by a cold-start test (sensor reached 600°F in 45 seconds).
6. Fixes for F-150's P0155
Resolve P0155 in your F-150 with these MA900-verified fixes—tailored to specific causes:
1. Replace Bank 2 Sensor 1 Oxygen Sensor
- Confirm heater failure via MA900’s O2 Sensor Heater Test.
- Locate the sensor (F-150-specific positions):
- 3.5L/2.7L EcoBoost: Passenger-side exhaust manifold, near turbo
- 5.0L V8: Passenger-side cylinder head, below air intake
- PowerBoost Hybrid: Integrated with exhaust manifold (remove heat shield first)
- Disconnect battery + let exhaust cool (45+ minutes for turbo models).
- Remove sensor with a 7/8" oxygen sensor socket (use penetrating oil for rusted units).
- Install OEM sensor with anti-seize (avoid heater element):
- 2015–2020 3.5L/5.0L: #BL3Z-9F472-A
- 2021–2023 3.5L/2.7L: #BL3Z-9F472-B
- PowerBoost Hybrid: #BL3Z-9F472-C
- Torque to 30 ft-lbs, reconnect battery, and clear codes with MA900.
2. Repair Wiring Harness (5.0L V8 Models)
- Use MA900’s Circuit Trace to find damaged sections (focus near engine mounts).
- Replace worn wire with Ford-spec heat-resistant 18-gauge wiring (#WPT-155).
- Secure harness to frame rail with new clips (#W706547-S300) to reduce vibration.
- Wrap repaired section with heat tape (#FT1646) to protect from exhaust heat.
- Verify repair with MA900’s continuity test before reassembly.
3. Replace Blown Fuse (2.7L EcoBoost)
- Locate engine bay fuse box (driver’s side near battery).
- Identify O2 heater fuse (#37, 15A) using F-150’s fuse diagram (MA900 has a built-in guide).
- Replace with OEM 15A fuse (#F5AZ-14526-A).
- Use MA900’s Fuse Circuit Test to check for underlying shorts.
- Clear codes and test drive to confirm fix.
7. Repair Costs & Maintenance Tips
F-150 P0155 repair costs vary by cause—use this table to budget:
| Repair Type | DIY Parts Cost | Professional Repair Cost | F-150 Models Affected |
|---|---|---|---|
| Bank 2 Sensor 1 O2 Replacement | $75–$140 (OEM) | $220–$350 (parts + 1.5hr labor) | All models (3.5L EcoBoost most common) |
| Wiring Harness Repair | $25–$50 (wire + clips) | $200–$300 (parts + 1.5hr labor) | 2015–2023 5.0L V8 |
| Fuse Replacement + Circuit Check | $5–$10 (OEM fuse) | $80–$150 (parts + 0.5hr labor) | 2018–2023 2.7L EcoBoost |
| Connector Cleaning/Repair | $15–$30 (cleaner + grease) | $120–$180 (parts + 1hr labor) | 2015–2020 Rust Belt models |
| ECU Software Update (TSB 21-1442) | $0 (with MA900) | $180–$250 (dealer fee) | 2021–2023 PowerBoost Hybrid |
| DIY Diagnosis with MA900 | $0 (one-time tool investment) | $150–$200 (dealer diagnostic fee) | All models |
Maintenance Tips for F-150 Owners
- 3.5L EcoBoost (2015–2020): Replace Bank 2 Sensor 1 every 80,000 miles (preventive).
- 5.0L V8: Inspect O2 sensor wiring every 30,000 miles—secure loose harnesses to reduce vibration wear.
- 2.7L EcoBoost: Check O2 heater fuse (#37) quarterly, especially before winter.
- Rust Belt models: Clean sensor connectors annually with dielectric grease to prevent corrosion.
- All F-150s: Avoid short trips in cold weather (let engine reach 200°F+ to protect heater elements).
- Perform MA900’s O2 Sensor Health Check every 6 months to catch issues early.
8. Preventive Maintenance for F-150
Avoid P0155 in your F-150 with these Ford-recommended steps:
-
Sensor Care:
- For 3.5L EcoBoost: Install an aftermarket heat shield (#3C3Z-9439-A) around Bank 2 Sensor 1.
- Replace O2 sensors every 100,000 miles (sooner if towing frequently).
- Use only OEM sensors—aftermarket units fail 2x faster in F-150’s high-temp environment.
-
Wiring & Fuse Maintenance:
- 5.0L V8: Replace wiring harness clips every 50,000 miles to reduce vibration.
- Keep engine bay fuse box clean—use compressed air to remove dirt/debris quarterly.
- Carry spare 15A fuses for O2 heater circuit (F-150: #F5AZ-14526-A) for emergencies.
-
Engine Operation:
- Let engine idle 1–2 minutes in cold weather before driving (warms sensor heater).
- Avoid towing heavy loads until engine reaches operating temp (200°F+).
- Use top-tier gasoline (87+ octane) to reduce exhaust deposits on sensor elements.
-
Software Updates:
- Check for Ford TSB updates every 6 months with MA900.
- Install ECM calibrations for heater circuits (e.g., TSB 21-1442 for hybrids) immediately.
9. F-150-Specific FAQs
Yes, but avoid cold weather and towing. P0155 doesn’t cause immediate damage, but slow sensor warm-up reduces fuel efficiency and can hide other issues. Fix within 2–3 weeks.
The 3.5L’s twin turbos create 1,200°F+ exhaust temps—30% higher than the 5.0L V8. This accelerates heater element degradation, which is why Ford released TSB 18-2349 for 2015-2020 models.
We recommend OEM sensors—aftermarket units often fail in 6–12 months. Ford’s OE sensors are calibrated for F-150’s high-temp exhaust, with heavier-gauge heater elements.
Yes—MA900 fully supports 2023 F-150 Raptor R and its 5.2L supercharged V8, including Ford’s latest diagnostic protocols for O2 sensor heater circuits.
