P0463 Code on a Cadillac: Fuel Level Sensor Circuit High (Cadillac Guide)

P0463 on a Cadillac is GM's "Fuel Level Sensor 1 Circuit High Voltage." The signal from the fuel tank's level sender has gone above the range a working sender can produce. You'll usually notice it as a fuel gauge stuck on empty, a low-fuel warning that won't go away, or a gauge that drops and recovers. Two Cadillac-specific facts change how you approach it. First, on many older Cadillacs, including the 2000–2005 Northstar cars and the 2004–2008 CTS, STS and SRX V6, GM's tables show P0463 does not turn on the check engine light, so you may only find it with a scan tool. Second, the cause is often not the sender. GM's bulletin for the 2017–2018 XT5 AWD says to replace the fuel pump, not the sending unit, and an Escalade gauge that drops in Park can be normal behavior.

What Does P0463 Mean on a Cadillac?

The fuel level sender is a float on an arm that sweeps a variable resistor inside the tank. The control module feeds it a reference voltage and reads back a voltage that changes with resistance. P0463 means that reading has gone too high, above what the sender can produce anywhere in its travel.

GM's 2019 table for the 3.6L V6 group (XT5, XT6, XTS, ATS, CTS, CT6) defines it as detecting "a primary fuel tank level sensor stuck out-of-range high." It counts a failure when the sender reads above 60% of the 5-volt range and sets the code at 100 failures in 125 samples, taken 100 ms apart. It is Type B, two trips.

A high reading usually means the circuit is open: a broken wire, a corroded or unplugged connector, a worn spot on the sender's resistor track, or a lost ground. To the module, an open circuit looks like the voltage floating high.

How the Fuel Level Signal Works

Many Cadillacs have more than one sender. AWD crossovers and some sedans use saddle-shaped tanks with a primary and a secondary side, each with its own level sensor. GM's codes follow that: P0461–P0464 are sensor 1 and P2066–P2068 are sensor 2. A transfer jet in the primary pump module moves fuel from the secondary side to the primary side.

On the 2017–2018 XT5 AWD, GM's bulletin gives a useful working range. Both level sensors should sweep from about 40 to 250 ohms, measured at the chassis-to-tank harness connector, X350. At 250 ohms GM reads the side as empty, and toward 40 ohms as full. Other Cadillacs use different senders and ranges, so use the specification for your VIN.

Depending on the model and year, the reading is taken by the ECM, the body or cluster module, or on 2021-and-later Escalades and XT models a separate fuel pump driver control module. That decides where you test.

Which Cadillacs Set P0463

We checked GM's OBD tables from 1997 to 2025. P0463 isn't in the 1997–1999 Northstar or Catera tables we read. It first shows up in the 2000 Northstar table and in the 2001 Catera (3.0L) table. From there it appears in every Cadillac gasoline group we checked: the Northstar DeVille, Seville, Eldorado, DTS, STS, XLR and SRX V8; the 3.2L and 3.6L CTS and STS; the 2.8L and 3.0L SRX; every later 3.6L, 2.0T, 2.7T and 3.0TT engine in the XTS, ATS, CT6, XT4, XT5, XT6, CT4 and CT5; and the Escalade, from the 2000 truck V8 table on.

The Lyriq and Optiq are electric and have no fuel sender.

Why Your Light May Not Be On

The tables show that whether P0463 turns on the check engine light depends on the year:

• 2000–2005 Northstar (DeVille, Seville, Eldorado): Type C, a non-emissions code that doesn't turn on the check engine light.
• 2002–2004 Escalade (truck V8 tables): also Type C.
• 2003 CTS 3.2L and the 2004–2008 3.6L and 2.8L V6 (CTS, STS, SRX): the MIL column for P0463 reads "no."
• 2006-and-later Northstar, the 2008-and-later Escalade group, the 2011 SRX 3.0L and later V6 tables such as 2014 and 2019: Type B, which turns on the light after two trips.

So on an older Cadillac with a dead fuel gauge and no warning light, P0463 can still be stored. A scan tool that reads all modules is worth having.

What GM's Cadillac Documents Say

2017–2018 XT5 AWD: blocked transfer jet (18-NA-365, February 2019). This bulletin covers the XT5 with the 3.6L LFY or LGX and AWD, alongside the Enclave, Traverse and Acadia. It names P0463 with P018B, P0461, P0462, P0464, P2066, P2067, P2068 and P2635. Owners may report stalling, poor performance, or a low range reading while the gauge shows adequate fuel. GM's cause is a partly or fully blocked port in the primary pump module's transfer jet, so fuel can't move over from the secondary side. Technicians check both sender resistances at X350 and confirm the primary sender sweeps freely. GM is explicit: if the primary pump is the cause, "only replace the pump and not the fuel level sending sensor."

2004–2005 XLR: erratic gauge with P0463 (GM bulletin 05-06-04-041, 2005). NHTSA's summary of this bulletin describes erratic fuel gauge readings, a gauge reading empty with fuel in the tank, P0463 and a "Service Fuel System" message on the 2004–2005 XLR. NHTSA has no copy of the bulletin, so we have seen only the summary. Other XLR documents in NHTSA's index cover revised fuel sender values and empty-gauge complaints on 2007–2009 cars.

2019 XT4: fuel level sensor program (N182201300, May 2019). This customer satisfaction program covered a small number of 2019 XT4s, where the fuel gauge may not accurately reflect the fuel in the tank because of a malfunctioning level sensor, and the car could run out of fuel unexpectedly. The fix is a new sending unit. The program ran until June 30, 2021, so it has ended, though a dealer VIN check is free. It doesn't name a DTC.

2002–2009 Escalade: gauge drops in Park or Neutral (PIT3046G, February 2015). GM's preliminary information covers the gauge falsely showing low, or dropping to E with the low fuel light on, mostly at or below a quarter tank, after fuel sloshes and the transmission is shifted. GM says that with an automatic, no buffering takes place in Park or Neutral and this is "a NORMAL characteristic & NO repairs are necessary." It doesn't involve P0463. If there is no code, don't replace a sender for this.

Gauge concerns without a code. GM also has PI0658 (2011–2012 Escalade and 2012 SRX, gauge slow or low after a fill), PI1401A (2013–2015 XTS, gauge only reaches 7/8 full) and 24-NA-139 (2021–2023 Escalade, XT4, XT5 and XT6, fuel gauge inoperative or erratic with P023F or P129F from the fuel pump driver control module). None of them names P0463, but each explains a gauge complaint that isn't a sender circuit fault.

For the Buick side of this code, see our Buick P0463 guide.

Symptoms of P0463

• Fuel gauge stuck on empty or reading erratically
• Low fuel warning on with fuel in the tank
• Range display wrong or very low
• Check engine light on newer models; often no light on 2000–2008 Cadillacs
• A "Service Fuel System" message on some models, such as the 2004–2005 XLR
• On a 2017–2018 XT5 AWD, possible stalling or loss of power if fuel isn't transferring

Causes and How to Confirm Each

How Is P0463 Diagnosed on a Cadillac?

1. Read codes from all modules. On older Cadillacs P0463 may be stored without a light. Note P0461–P0464 and P2066–P2068 together.
2. Check the VIN for bulletins. On a 2017–2018 XT5 AWD, follow 18-NA-365. On a 2019 XT4, check N182201300. On a 2004–2005 XLR, ask about 05-06-04-041.
3. Watch the fuel level data on a scan tool. A reading pinned at the top of its range points to an open circuit.
4. Measure sender resistance at the tank connector. Compare it with the specification for your VIN. On the XT5 AWD, GM's range is about 40–250 ohms.
5. Check the wiring and connector between the tank and the module that reads the sender.
6. On a dual-sender tank, compare both sides. One side empty and the other holding fuel is a transfer problem, not a sender problem.
7. Replace only what the tests condemn. GM's XT5 bulletin is clear that the pump, not the sender, is the part when the jet is blocked.
8. Clear the codes and confirm that the gauge tracks a known amount of fuel added.

Parts and Cost

GM Documents Relevant to P0463 on a Cadillac

Have a dealer check your VIN against current bulletins and campaigns rather than relying on any article, including this one.

What Other P0463 Pages Get Wrong

• "Replace the sending unit." On the 2017–2018 XT5 AWD, GM says to replace the pump, not the sender, when the transfer jet is blocked.
• "It always lights the check engine light." Not on many 2000–2008 Cadillacs, according to GM's own tables.
• Treating every gauge problem as P0463. GM documents explain Escalade gauge drops in Park as normal, and 2021–2023 gauge failures with P023F/P129F as a fuel pump driver module issue.
• Skipping the connector. A high reading usually means an open circuit, so check the wiring before ordering a tank part.

Frequently Asked Questions

Is it safe to drive with P0463?

The engine usually runs normally, but you can't trust the gauge. Track mileage from each fill-up so you don't run dry, and get it fixed. Running out of fuel can also be hard on the fuel pump.

Why is there no check engine light with my P0463?

On 2000–2005 Northstar cars, 2002–2004 Escalades and 2003–2008 V6 CTS, STS and SRX models, GM's tables list P0463 as a code that doesn't turn on the light. Newer Cadillacs use a two-trip Type B code that does.

My XT5 says I have no range but the gauge shows fuel. What's wrong?

On 2017–2018 XT5 AWD models, GM's 18-NA-365 describes a blocked transfer jet in the primary pump module that leaves fuel stranded on the secondary side. The repair is the primary pump module.

Can a bad ground cause P0463?

Yes. Anything that opens the sender circuit, including a ground, can make the reading float high.

Do I have to drop the tank?

Often, to replace the sender or pump module. But test the wiring and connector first, which usually doesn't require dropping the tank.

My Escalade gauge drops when I park. Is that P0463?

Not if there's no code. GM's PIT3046G says that on 2002–2009 Escalades with an automatic, the gauge isn't buffered in Park or Neutral, so fuel slosh can make it read low. GM calls that normal.