A P0463 code means the engine computer sees a fuel level sensor signal above its normal range, so the fuel gauge can show more fuel than the tank holds. The exact wording varies by manufacturer, and the same code is also written as Fuel Level Sensor A Circuit High.
Gauge symptoms are the clearest sign, but on some GM all-wheel-drive models the cause can sit in the fuel pump module. The steps below help you tell a P0463 code caused by a sender or wiring fault from one caused by a pump fault.
Fuel system work carries a fire risk. Use these checks for diagnosis, and have a qualified technician handle tank or pump removal.
What the P0463 code means
P0463 means the fuel level sensor circuit reads a voltage above its expected range, so the computer believes the tank holds more fuel than is possible. General Motors names the P0463 code Fuel Level Sensor 1 Circuit High Voltage in its service bulletin 18-NA-365. Repair guides also call it Fuel Level Sensor A Circuit High, and they note that the exact definition can vary by manufacturer.
Because the signal is above range, a P0463 code can show a level that does not match the real tank. Check your vehicle’s service information before you rely on a wording match alone.
A P0463 code concerns the fuel level signal, not fuel pressure or the air-fuel mix that short term fuel trim data describes. That difference matters, because a fuel pressure fault (see fuel pressure sensor replacement costs) and a level sensor fault call for different checks. The P0193 code guide explains the separate fuel rail pressure sensor circuit.
Symptoms that come with P0463
The clearest sign is a fuel gauge that reads wrong, and the check engine light may come on with it. The table separates what the GM bulletin lists for a P0463 code from what repair guides report.
| Symptom | Where it is documented | Notes |
|---|---|---|
| Low range or mileage shown when the gauge shows adequate fuel | GM bulletin 18-NA-365 | Listed as a customer concern for 2017-2018 AWD models |
| Stalling | GM bulletin 18-NA-365 | Listed for the affected group only |
| Lack of engine performance | GM bulletin 18-NA-365 | Some repair guides say performance is usually unaffected |
| Malfunction indicator lamp on | GM bulletin 18-NA-365 | Listed as a customer concern |
| Gauge reads full, jumps or flickers | Repair guides (fs1inc, carparts.com) | Reports from repair sites, not manufacturer data |
The bulletin covers 2017 and 2018 model years only, so a stall on a different car does not prove the same cause. Repair sites describe gauges that read full or flicker while driving, but they do not give manufacturer data for those patterns.
Common causes of P0463
The sender, its wiring and connector, and the fuel pump module are the main suspects, and a GM bulletin ties one AWD case to the pump. For a P0463 code, repair guides usually list four groups: a faulty sending unit, corroded or loose wiring and connectors, a poor ground, and a computer fault. Some guides add voltage spikes from alternator problems.
The GM AWD fuel pump case
GM bulletin 18-NA-365 links a P0463 code and related codes to a partly or fully blocked port in the primary in-tank fuel pump module’s transfer jet manifold. It covers 2017 and 2018 Buick Enclave, Cadillac XT5, Chevrolet Traverse and GMC Acadia models with AWD (RPO F48) in North America. Read the full bulletin in the GM service bulletin 18-NA-365.
The bulletin says the blocked jet stops fuel transfer from the secondary side of AWD tanks. That is why the fix targets the primary pump module, and the sender is left in place when the pump is at fault. For a general pump check, see how to test a fuel pump.
The bulletin does not apply to other vehicles or model years. If your car is outside that scope, do not assume the same cause fits it.
Is P0463 safe to drive with?
A P0463 code does not by itself make the car unsafe, but the gauge can mislead you and stalling is a listed concern on the affected GM models. The main practical risk with a P0463 code is running out of fuel when the gauge reads too high.
Until the gauge is checked, track the miles driven since your last fill-up and refuel early rather than waiting for the gauge to drop. This keeps you from relying on a reading you cannot yet trust.
If the engine stalls, especially in traffic, pull over when it is safe to do so and have the vehicle inspected before the next trip.
How to diagnose P0463 step by step
Start with a scan for the P0463 code and related fuel codes, then check the sender circuit before you replace any part. The steps combine repair-guide advice with the GM bulletin.
- Scan the engine computer and write down P0463 along with any related fuel codes. The GM bulletin lists P0461, P0462, P0464, P2066, P2067 and P2068 among related codes.
- Inspect the sender connector and wiring for corrosion, bent pins, chafing and loose fits.
- Measure sender resistance using the service manual for your vehicle. On the GM AWD models in the bulletin, both level sensors sweep from about 40 to 250 ohms.
- On those AWD models, the bulletin treats both sensors at 250 ohms as an empty tank, so compare each reading with the real fuel level before you condemn a part.
- Repair the wiring or the pump module as the tests show for the P0463 code. If the pump is the cause, replace only the pump, not the level sender.
| Check | What it tells you |
|---|---|
| Scan for P0463 and related codes | Whether the fault is limited to the sender circuit or part of a wider fuel system problem |
| Connector and wiring inspection | Corrosion, damage or loose pins that can mimic a sensor fault |
| Sensor resistance sweep (40 to 250 ohms on the bulletin’s models) | Whether each sender moves freely through its range |
| Pump module transfer jet check (in-scope AWD only) | Whether the blocked port explains the stuck fuel reading |
Repair guides advise troubleshooting before any sender replacement, because on many vehicles the sender sits inside the tank and the tank must come out to reach it.
Fuel system safety before you start
Fuel vapor is highly flammable, so work near the tank only with the engine off, away from ignition sources, and with a Class B extinguisher nearby. The bulletin gives these warnings, and it is written for trained technicians.
- Keep a Class B dry chemical fire extinguisher within reach.
- Never drain or store gasoline in an open container.
- Keep sparks, open flames and hot exhaust parts away from the work area.
- Leave tank lowering and pump removal to a qualified technician if you lack a lift and the right tools.
What a repair involves and what to ask a shop
Many P0463 repairs need the fuel tank lowered or removed, so plan for a shop visit and a written estimate. The table shows which repair path fits which finding.
| Repair path | When it fits |
|---|---|
| Wiring or connector repair | Corrosion, damage or loose pins found during inspection |
| Level sender replacement | The sender fails the resistance checks and the wiring is sound |
| Primary fuel pump module replacement | An in-scope AWD model showing the blocked transfer jet pattern from the bulletin |
The bulletin lists 2.7 hours for fuel pump replacement as a warranty labor operation, while the guide to fuel pump replacement costs covers typical shop pricing. That number is a labor standard for warranty claims, not a shop price, and it leaves out parts. The sources checked here did not give verified, dated repair prices, so compare written estimates from shops in your area.
Ask the shop which readings they took, whether the GM bulletin applies to your VIN, and whether they checked the wiring before recommending a sender or a pump.
Frequently Asked Questions
Is P0461 the same as P0463?
No. P0461 is the fuel level sensor performance code, while the GM bulletin names P0463 as Fuel Level Sensor 1 Circuit High Voltage. P0461 points to how the sensor performs, while P0463 points to a signal that is too high. Both appear in the bulletin’s list of related codes, so read them together with the sensor test.
Does a P0463 code always mean the fuel sender is bad?
No. The GM bulletin ties the P0463 code family to a blocked port in the primary fuel pump module on some AWD models. Repair guides also list corroded wiring, poor grounds and computer faults. Replacing the sender without the checks can leave the real cause in place, so test the circuit first.
Does a P0463 code affect engine performance?
Sources disagree. The GM bulletin lists stalling and lack of engine performance for its affected 2017-2018 models. Some repair guides say performance is usually unaffected and the problem is mainly the gauge. If your car stalls or runs poorly, treat that symptom seriously and have it inspected.
Which vehicles does the GM bulletin cover?
GM bulletin 18-NA-365 covers 2017 and 2018 Buick Enclave, Cadillac XT5, Chevrolet Traverse and GMC Acadia models with AWD (RPO F48) in North America. Other model years and drivetrains fall outside its scope. Check your VIN with a dealer or a shop before applying its steps.
Should I replace the fuel level sender first?
Not before the checks. The GM bulletin says that when the primary pump is the cause, you should replace only the pump and not the fuel level sending sensor. Test the wiring, connector and sender resistance first, then decide which part, if any, needs replacing.
Will clearing a P0463 code fix it?
No. Clearing the check engine light only removes the stored message. If the fault is still present, the computer sets the code again. Fix the cause first, then clear the code and confirm that the gauge and the scan stay normal on a test drive.
Use the bulletin as a guide only for vehicles in its scope. For any other P0463 code case, the wiring, sender and pump checks above still apply, and a technician with the service manual can confirm the correct values before parts are replaced.
