P0024 Code on a Buick: Exhaust Camshaft Position System Performance, Bank 2 (Buick Guide)

P0024 is GM's "Exhaust Camshaft Position System Performance, Bank 2." It means the engine computer commanded the bank 2 exhaust cam phaser to a position and the camshaft did not get there. On a Buick it can only come from the 3.6L V6 — the Enclave, the LaCrosse, the Rendezvous 3.6L and the 2018–2020 Regal GS — because that is the only Buick engine with a bank 2 exhaust phaser. And GM's own documents for those Buicks carry a surprise: several say the right answer is not a new cam actuator. On some 2012–2015 LaCrosses GM says check a letter on the engine sticker first; on 2018 Enclaves and LaCrosses, GM traced P0024 to software and to electrical noise on the crank sensor wiring.

What Does P0024 Mean on a Buick?

Each camshaft on the Buick 3.6L has a phaser (GM calls it the camshaft position actuator) on its front end. Engine oil, metered by an oil control valve — the camshaft position actuator solenoid valve — moves the phaser to advance or retard the cam. The ECM sets a target, watches the cam sensor, and compares the two.

GM's 2015 OBD monitor summary for the 3.6L describes P0024 exactly that way: the ECM takes the absolute difference between desired and actual exhaust cam position on bank 2 and fails the test when the error exceeds a calibrated limit in 100 of 300 samples, taken every 100 ms. The test only runs when the engine is running, system voltage is above 11 volts and the desired position is steady. It is a two-trip code.

So P0024 is a control code: the phaser was asked to move and did not follow. That is different from P0019, which checks bank 2 exhaust cam timing against the crank with the phaser parked. The usual suspects are the oil control valve, the oil feeding it and the phaser itself — but on Buicks GM has added a few more.

Which bank is bank 2? On the 3.6L, bank 1 holds cylinders 1-3-5 and bank 2 holds 2-4-6. GM's documents call bank 2 the left side. In the transverse Enclave, LaCrosse and Regal GS, that is the front bank, toward the radiator.

Which Buicks Can Set P0024

• Enclave 2008-on with the 3.6L (LY7, LLT, then LFY from 2018).
• LaCrosse with the 3.6L — LY7 in the 2005–2009 CXS, LLT and LFX in 2010–2016, LGX in 2017–2019.
• Regal GS 2018–2020 with the 3.6L LGX.
• Rendezvous and Allure (Canada) with the 3.6L LY7.

Four-cylinder Buicks have no bank 2. The 3800, 3.5L and 3.9L pushrod V6s have one camshaft in the block, so they cannot set a bank 2 exhaust cam code. If a scan tool reports P0024 on an Encore, Verano or four-cylinder Regal, re-read the code.

2012–2015 LaCrosse: Check the EUN Sticker First

GM's preliminary information PIP5096 went through four revisions; the last, PIP5096C, covers the 2012–2015 LaCrosse with the 3.6L LFX (plus several Cadillac and Chevrolet models). The condition: a check engine light with P0011, P0014, P0021 or P0024 and no drivability complaint.

GM's instruction is to inspect the engine EUN sticker before replacing the actuator. If there is an "A" in front of the sequence number, replace the oil control valve (cam actuator solenoid valve) with a replacement service valve. GM's reason: the service valve is from a different supplier and "can make up the difference in the clearance that causes this concern." The bulletin adds, in capitals, "DO NOT JUST SWAP FROM ANOTHER LOCATION." If the service valve does not cure it, continue with normal diagnosis.

That is the opposite of the usual internet advice — swap the bank 1 and bank 2 valves to see if the code moves. On these engines GM is telling technicians the clearance issue is in the original valve design, so a swap proves nothing and a new service valve is the test.

Special Coverage 16115 (2014 LaCrosse)

GM later turned the LaCrosse problem into a warranty extension. Special Coverage 16115 (December 2016) covers some 2014 LaCrosse (and Impala) models with the 3.6L LFX where P0014 or P0024 sets because of a sticking exhaust camshaft position actuator solenoid valve. Dealers replace only the valve matching the code that set, using part 12636175.

The coverage ran 10 years or 120,000 miles from the original in-service date. For a 2014 model, that term has passed for practical purposes. A dealer VIN check is still free, and it will show whether the valves were already replaced under the program.

The coverage also shows how much harder bank 2 is to reach on the LaCrosse: GM's labor allowance was 0.6 hour for the bank 1 exhaust valve and 1.6 hours for bank 2.

2007–2010 Enclave and LaCrosse: Camshaft End Play

On the early 3.6L, GM bulletin 08-06-01-011K covers a check engine light with P0011, P0014, P0021, P0024, P0341, P0346, P0366 or P0391. It names the 2007–2010 Enclave, 2007–2009 LaCrosse and Allure, and the 2010 LaCrosse with the LY7 or LLT.

GM's sequence:

1. On an Enclave with P0011, P0014, P0021 or P0024, first reprogram the ECM (GM refers to bulletin 08-06-04-011). If the codes stop, the job is done.
2. If they return, remove the cam cover on the bank that set the code and measure camshaft end play. GM's limit is 0.40 mm (0.016 in).
3. If end play is at or over the limit, check the gap between each actuator and the front cam cap with a 2.0 mm (Delphi, 4-screw actuator) or 2.5 mm (Aisin, 5-screw) hex wrench.
4. If the wrench does not fit, install camshaft thrust washers. If it does fit, the cylinder head is replaced and thrust washers installed.

A camshaft that walks back and forth in its bearings will not hold the position the phaser asks for, which is why end play sets performance codes. The same thrust-washer fix appears in GM's timing chain bulletin 12-06-01-009F for heads built before June 5, 2009. A related GM index entry, PIP4333, lists the same code group for the LY7 and LLT.

2017–2018 LaCrosse, Regal GS and Enclave

The second-generation 3.6L brought auto stop/start, and GM's P0024 documents changed with it.

Software (PIP5568E and N192266190). PIP5568E covers the 2018 Enclave (LFY), 2017–2018 LaCrosse (LGX) and 2018 Regal (LGX). The SES light may come on by itself, or the driver may feel a stall, lurch, stumble, hesitation or power loss after an auto stop/restart. GM describes all four phaser codes — P0011, P0014, P0021 and P0024 — setting together or in pairs as history codes. The cause is a software condition: after a restart the ECM does not regain full cam "sync," reports cam position as zero and keeps commanding the actuators. GM's instruction was to check for other concerns, then clear the codes and return the vehicle. GM then released Service Update N192266190 for the 2018 LaCrosse and Enclave: reprogram the ECM, because the stop/start software issue can cause rough running, reduced power or a rare stall, and P0011, P0021, P0014 and P0024 may set. Updates of this kind run for the New Vehicle Limited Warranty period, which has passed on 2018 models, but a dealer can see whether it was done.

Crank sensor wiring (17-NA-317). For the 2018 Enclave LFY, GM bulletin 17-NA-317 lists P0011, P0014, P0021, P0024, P034B, P0506 and P0557, with symptoms including transmission shudder above 40 mph, low idle or stalling after auto start, Reduced Engine Power and Service Brake Assist messages. GM's cause is the crankshaft position sensor circuit picking up electrical interference from another circuit in the same harness. The fix is a twisted-pair jumper harness between the crank sensor and the ECM, plus a G109 ground inspection. A cam actuator would never have fixed that P0024.

If your 2018 Enclave has P0024 and also stalls after auto stop, read our Traverse, Acadia and Enclave stall explainer.

Symptoms of P0024 on a Buick

• Check engine light with no other complaint (common on 2012–2015 LaCrosse)
• Rough running, hesitation or stall right after an auto stop/restart (2017–2018 LGX/LFY)
• Transmission shudder, low idle, Reduced Engine Power or Service Brake Assist messages (2018 Enclave crank sensor wiring)
• P0014, P0011 or P0021 set alongside it

Causes and How to Confirm Each

How Is P0024 Diagnosed on a Buick?

1. Confirm the engine. Only a 3.6L Buick can set P0024 for real.
2. Record all codes and whether they are current or history. GM's 2018 software PI only applies to history codes; P034B or P0557 alongside points at 17-NA-317.
3. Ask a dealer for a VIN check. N192266190, Special Coverage 16115 and earlier ECM updates are all tracked by VIN.
4. Check the oil level and condition before anything else.
5. On a 2012–2015 LaCrosse, read the EUN sticker on the engine for the "A" before the sequence number.
6. Compare commanded and actual exhaust cam angle on bank 2 with a bidirectional scan tool. A phaser that follows when commanded points away from the mechanical parts.
7. On a 2007–2010 engine, follow 08-06-01-011K: ECM update on the Enclave, then end play.
8. Replace an actuator last, once GM's documented causes for your model are ruled out.

Parts and Cost

GM Documents That Name P0024 on Buick Models

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

What Other P0024 Pages Get Wrong

• "Swap the bank 1 and bank 2 solenoids to test." For the 2012–2015 LaCrosse, GM says do not just swap; fit the service valve when the EUN sticker shows an "A."
• "P0024 means a bad cam phaser." GM's Buick documents point at the valve, end play, software and crank sensor wiring before the phaser.
• Treating P0024 as a timing chain code. It is a control code; chain stretch shows as P0008/P0019-type correlation codes.
• Listing P0024 for four-cylinder Buicks. Only the 3.6L has a bank 2 exhaust phaser.
• Getting the bank wrong. Bank 2 is the left bank in GM's terms — the front, radiator-side bank in a transverse Enclave or LaCrosse.

For the bank 1 version of this fault, see our P0014 GM guide.

Frequently Asked Questions

Is P0024 serious on a Buick Enclave or LaCrosse?

Usually it is not an emergency. GM's 2012–2015 LaCrosse document describes it with no drivability concern. But on a 2018 Enclave, if it comes with stalling after auto stop or transmission shudder, get it checked promptly.

Where is bank 2 on my Buick?

On the 3.6L, bank 2 is cylinders 2-4-6 — the left bank in GM's terms. In a transverse Enclave, LaCrosse or Regal GS that is the front bank, nearest the radiator.

Is P0024 covered by a GM warranty extension?

Special Coverage 16115 covered some 2014 LaCrosse models for 10 years or 120,000 miles; that term has passed for practical purposes. A dealer VIN check for any open update is free.

Can software cause P0024?

Yes. GM documented a stop/start software condition on the 2017–2018 LaCrosse, 2018 Enclave and 2018 Regal GS, and reprogrammed 2018 LaCrosse and Enclave ECMs under N192266190.

What is the difference between P0024 and P0019?

P0024 means the bank 2 exhaust phaser did not reach its commanded position. P0019 means the bank 2 exhaust cam is out of time with the crank while the phaser is parked — usually chain or reluctor trouble.

Can low oil cause P0024?

Yes. The phaser is moved by oil pressure, so low or degraded oil makes it slow to respond — exactly what P0024 measures.

Can I clear P0024 and keep driving?

You can clear it, and on the 2018 software condition GM's own first step was to clear and release. If it returns as a current code, follow the diagnosis above.