P0051 on Nissan: Causes, Symptoms and Fix Cost
Quick Answer
Safe to drive (short-term)
P0051 on a Nissan means the engine computer sees too little current in the heater of the front oxygen sensor on bank 2, the side of a V or flat engine that does not hold cylinder 1. Only engines with two cylinder banks can set it. The heater brings the sensor to working temperature quickly after a cold start, and without it the mixture runs on fixed values for longer. The usual causes are a burned-out heater, an open wire, or a failed sensor relay or fuse. A new front sensor on this bank typically costs 130 to 400 EUR fitted.
- Severity
- Low · Emissions
- Typical repair cost, all makes
- €1-€400
Connect a standard OBD2 adapter (Bluetooth LE on iPhone) to your Nissan and Skanyx tells you what P0051 means on that engine, whether it is safe to keep driving, and what the fix should cost. Free on iPhone and Android.
Get Skanyx freeWhat does P0051 mean on a Nissan?
The Quick Answer above is the generic definition. What follows is the model-specific detail for the Nissan models that log P0051.
Nissan 350Z (VQ35HR V6)
2007-2009
Nissan's 2007 service manual lists P0051 for the bank 2 air-fuel ratio (A/F) sensor 1 heater, a wideband sensor, not a plain two-state oxygen sensor. Its test order is the body grounds, battery voltage at the sensor plug with the key on (checking the 15 A fuse and harness if it is missing), continuity of the heater wire to the computer, then the heater itself.
Source: 350z.se, en.wikipedia.org
Sources
- 350z.se 350z.se/fsm/coupe/2007/ec.pdf
- en.wikipedia.org en.wikipedia.org/wiki/Nissan_350Z
What causes P0051 on a Nissan?
Beyond the generic causes listed on the main P0051 page, these are the patterns noted for Nissan models:
Open or shorted air-fuel ratio sensor 1 heater
: Nissan 350Z (VQ35HR V6)
Open 15 A fuse or damaged wiring between fuse and sensor
: Nissan 350Z (VQ35HR V6)
How to diagnose P0051 on a Nissan with OBD2
- Confirm which side is bank 2. It is the cylinder bank that does not contain cylinder 1, so the owner's manual or an engine diagram decides it, not left or right. Check that the code is not stored together with a bank 1 heater code, which would point to a shared fuse or relay
- Find the sensor heater fuse and relay in the fuse box diagram and test them. A fuse that keeps blowing means a short in the heater or its wire
- Unplug the bank 2 front sensor and measure the resistance across the two heater pins against the maker's value. One Toyota procedure for a V6 gives 1.8 to 3.4 ohms; other makes differ, so use your car's figure. An open circuit means the heater has failed
- With the key on, check for supply voltage on the heater power pin of the harness plug. No voltage points to the fuse, relay or supply wire
- Check continuity of the heater control wire from the sensor plug to the engine computer, and look for chafing, melted insulation or pins pushed back in the connector
- If sensor and wiring test good, check every ground that serves the engine computer before condemning it. In a published case on a Lexus ES 350 V6, P0051 survived two new sensors and three replacement computers until a missing ground at the engine computer was found
- After the repair, clear the code, do a cold start and a normal drive, and use a generic reader to confirm the heater monitor completes and the fuel system reaches closed loop
How much does P0051 cost to fix on a Nissan? (EUR)
Estimated repair costs for P0051 in EUR, compiled across makes. Expect Nissan parts and labour towards the upper end of each range.
| Repair | Parts Cost | Labor Cost | Total Estimate | DIY Difficulty |
|---|---|---|---|---|
| Replace sensor heater fuse | €1–€3 | €0–€0 | €1–€3 | Easy |
| Replace sensor heater relay | €10–€40 | €20–€60 | €30–€100 | Easy |
| Repair wiring or connector | €5–€20 | €40–€120 | €45–€140 | Moderate |
| Replace front air-fuel or oxygen sensor (Bank 2) | €80–€300 | €50–€100 | €130–€400 | Moderate |
| Workshop circuit diagnosis (power, ground and heater current) | €0–€0 | €60–€120 | €60–€120 | Professional |
Prices estimated as of October 2026. Costs vary by region, vehicle, and shop.
Codes related to P0051
These codes are often seen alongside P0051 or point to related issues, on any make:
Looking for the full P0051 reference (all makes, full diagnosis flow, complete repair cost matrix)? See the main P0051 guide