P0643 on NISSAN XTERRA — Sensor Reference Voltage A Circuit High

Q: "What does P0643 mean on a NISSAN XTERRA?"

"P0643 indicates: Sensor Reference Voltage A Circuit High. This is a computer and output circuits code. 2 NISSAN XTERRA owners have reported this to NHTSA."

Q: "What are the most common causes of P0643 on NISSAN XTERRA?"

"Based on 2 NHTSA reports, the most commonly cited components are: Engine And Engine Cooling, Steering,Fuel System, Gasoline,Equipment. These percentages are based on the component field in owner complaints."

Q: "Is P0643 serious on my NISSAN XTERRA?"

"Of 2 NHTSA reports for this code on NISSAN XTERRA, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic."

Q: "What should I do if my NISSAN XTERRA shows P0643?"

"1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare."

What P0643 Means on Your NISSAN XTERRA

P0643 is a diagnostic trouble code indicating: Sensor Reference Voltage A Circuit High. This code relates to the computer and output circuits system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

2 NISSAN XTERRA owners have reported this issue to NHTSA across model years 2005-2006. Most reports come from the 2005, 2006 model years. The most commonly reported component is Engine And Engine Cooling (50.0% of reports).

Real NISSAN XTERRA Owner Reports

Source: NHTSA Complaints Database

"Error code on 2005 nissan xterra - p0643 has shown up on many models with this engine. noted on an emission inspection for annual tx inspection."

— 2005 NISSAN XTERRA owner · ENGINE AND ENGINE COOLING · Filed 06/29/2008

"Nissan xterra 2006, both front cats have failed. dealer said due to ethanol a common problem, cost around $2300. found cats and a mechanic for $1200. after 3 weeks check engine light returned. i am now getting a p0643."

— 2006 NISSAN XTERRA owner · STEERING,FUEL SYSTEM, GASOLINE,EQUIPMENT · Filed 01/30/2011

All reports filed by vehicle owners directly with the U.S. Department of Transportation.

📊 Complaint Trend by Model Year

1

'05

1

'06

Common Causes on NISSAN XTERRA

Based on NHTSA complaint component analysis for this vehicle.

ENGINE and ENGINE COOLING 50%

STEERING,FUEL SYSTEM, GASOLINE,EQUIPMENT 50%

What To Do Next

1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.

Frequently Asked Questions

What does P0643 mean on a NISSAN XTERRA? ▾

P0643 indicates: Sensor Reference Voltage A Circuit High. This is a computer and output circuits code. 2 NISSAN XTERRA owners have reported this to NHTSA.

What are the most common causes of P0643 on NISSAN XTERRA? ▾

Based on 2 NHTSA reports, the most commonly cited components are: Engine And Engine Cooling, Steering,Fuel System, Gasoline,Equipment. These percentages are based on the component field in owner complaints.

Is P0643 serious on my NISSAN XTERRA? ▾

Of 2 NHTSA reports for this code on NISSAN XTERRA, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic.

What should I do if my NISSAN XTERRA shows P0643? ▾

1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare.

P0643 on Other Vehicles

→ All codes reported on NISSAN XTERRA