P0302 Code on a Cadillac: Cylinder 2 Misfire Detected (Cadillac Guide)

P0302 on a Cadillac means "Cylinder 2 Misfire Detected." On most cars that is just a cylinder number. On a 2016-or-later Cadillac with the Gen 2 3.6L or 3.0L twin-turbo V6 (ATS, CTS, CT5, CT6, XT5, XT6), it is a strong clue. GM says cylinders 2 and 5 are the Active Fuel Management cylinders on these engines. GM wrote bulletin 21-NA-036 specifically for P0302 and P0305. The causes it describes are a broken AFM oil control solenoid in the camshaft cover and rocker arms that don't latch, not a bad coil. On an Escalade, by contrast, cylinder 2 is not an AFM cylinder, which changes where you look. This guide covers where cylinder 2 is on each Cadillac engine, the GM documents that name it, and the right test order.

What Does P0302 Mean on a Cadillac?

The ECM counts crankshaft slowdowns at the moment cylinder 2 should fire. When those misfires cross GM's threshold, P0302 sets, usually with P0300. Any OBD-II gasoline Cadillac can set it, from a Northstar DeVille to a four-cylinder XT4. What makes P0302 different on many late-model Cadillacs is the cylinder deactivation hardware on that cylinder. For multi-cylinder misfires, use our P0300 Cadillac hub.

Where Cylinder 2 Is on Your Cadillac

On a Gen 2 V6, notice that the two AFM cylinders sit on opposite banks: cylinder 2 on bank 2 and cylinder 5 on bank 1. GM's swap test (below) uses exactly that.

The Gen 2 V6 AFM Story: GM Bulletin 21-NA-036

Bulletin 21-NA-036 covers the 2016–2019 ATS and CTS (LGX), 2020–2022 CT5 (3.0TT LGY), 2016–2020 CT6 (LGW, LGX), 2017–2022 XT5 and 2020–2022 XT6 (LGX). GM is explicit: it "only addresses concerns with misfires on cylinders number 2 and/or 5, which are the active fuel management cylinders," and the misfires "may be all the time or after an AFM/V4 mode event." The DTCs are P0300, P0302 and P0305.

GM gives two causes:

1. Oil leaking past the AFM oil control valve (OCV) solenoid in the camshaft cover. Oil pressure bleeds off, and the cylinder deactivates when it shouldn't. GM found solenoids that came out with the end broken off and stuck in the bore. The leftover piece is held only by its O-ring and can usually be pulled with a pick or snap-ring pliers.
2. Rockers on that cylinder not latching. GM's check is to remove the cam cover and turn the engine by hand while watching cylinder 2's rockers and valves. If any valve doesn't open or a rocker is broken at the latch pin, GM replaces all four switching roller finger followers (SRFFs) and all four stationary lash adjusters (SHLAs) on that cylinder. GM adds that if the misfire only happens coming out of AFM mode, the rockers can still be the cause.

For 2021–2025 CT5 (LGY) and XT5/XT6 (LGX), the later PIP5824D (February 2025) says GM "determined there is an issue with some rockers / SRFF's." It adds that the misfire can show up on a cold start and then go away. GM's first step is a free one: swap the AFM rocker oil control solenoids side to side in the cam covers. If the misfire disappears or moves to the other bank (P0302 becoming P0305), the solenoid is bad. If it stays on cylinder 2, check that cylinder's valves. Our P0305 guide covers the rocker parts GM lists.

The older PIP5486F ties a tick or rattle with P0300, P0302 or P0305 on the AFM cylinders to spongy lash adjusters, damaged SRFFs or a left-bank timing chain tensioner gasket on 2016–2019 ATS, CTS, CT6 and XT5 engines.

The #2 Injector Wiring Chafe on the LGX

Cylinder 2 has a second GM story. PIP5386A covers the 2016 ATS and CTS and the 2017 XT5 with the 3.6L LGX. It describes P0264 or P0265 (cylinder 2 injector circuit codes) together with P0300. The cause is a wiring concern at the #2 fuel injector: the harness can rub on the water outlet bolt boss. GM's repair is to remove the intake manifold, inspect the #2 injector wiring, insulate and wrap any chafed section, and protect the boss with high-temperature tape. If your P0302 comes with P0264 or P0265, look there before anything else.

Cylinder 2 on Other Cadillac Engines

Escalade and V-series V8

Cylinder 2 is not one of the AFM cylinders on the 2007–2020 Escalade, CTS-V LT4 or CT5-V. A collapsed AFM lifter is therefore not GM's documented explanation for a P0302 on those engines. The exception is the 2021-and-later Escalade 6.2L L87. Its Dynamic Fuel Management can deactivate any cylinder, and 23-NA-043 lists P0302 among the codes for collapsed or separated lifters on 2021 Escalades built September 1, 2020 through March 31, 2021.

CT6 4.2L twin-turbo

GM's 20-NA-038 lists cylinder 2 as a deactivating cylinder on the LTA. GM's 19-NA-253 gives a relative compression test for 2019–2020 CT6 4.2L misfires (P0300–P0308) to decide whether a misfire is mechanical before parts are replaced.

First-generation V6 and four-cylinders

On LY7, LLT, LFX and LF1 V6 engines, cylinder 2 is an ordinary cylinder. GM's single-cylinder tips for the LFX (PIP5062C) and coil heat-damage bulletin for the LLT (PIP5038B) apply to it like any other. On the CT4, 25-NA-037 lists P0302 with a ticking exhaust roller follower.

Symptoms of P0302

• Check engine light; flashing with a heavy misfire
• A misfire that starts or worsens right after the engine leaves four-cylinder (V4) mode on a Gen 2 V6
• Cold-start roughness that fades (PIP5824D notes this on 2021–2025 engines)
• Rough idle, a tick or tap from the cam cover area
• Cylinder 2 injector circuit codes P0264/P0265 alongside P0302 (LGX wiring chafe)

Causes and How to Confirm Each

How Is P0302 Diagnosed on a Cadillac?

1. Check the RPO code. LGX, LGW or LGY means cylinder 2 is an AFM cylinder.
2. Note when it misfires — all the time, after AFM events, or only on a cold start.
3. Rule out ignition and fuel first. Swap the coil and plug and run an injector balance test. GM's bulletins assume this is done.
4. Look for P0264/P0265. On an LGX, inspect the #2 injector harness per PIP5386A.
5. Swap the AFM oil control solenoids between the cam covers and re-test (PIP5824D).
6. Inspect the solenoid and its bore for a broken end or porosity (21-NA-036).
7. Remove the bank 2 cam cover and watch cylinder 2's valves while turning the engine by hand. If a valve doesn't open, the rockers and lash adjusters on that cylinder are replaced as a set.
8. Verify under the same conditions, including an AFM event, and check your VIN for bulletins.

Parts and Cost

GM Documents That Name P0302 or Cylinder 2 on Cadillacs

Have a dealer check your VIN for open recalls and bulletins. The check is free, and it is more reliable than any article, including this one.

What Other P0302 Pages Get Wrong

• "Start with a new coil." On a Gen 2 V6, a P0302 that appears after AFM events is GM's AFM-cylinder pattern. A coil swap is fine as a test but rarely the answer.
• "AFM is only on V8s." Cadillac's Gen 2 V6 deactivates cylinders 2 and 5.
• "Replace the one broken rocker." GM's instruction is all four rockers and all four lash adjusters on the affected cylinder.
• "Escalade P0302 means an AFM lifter." Not on 2007–2020 AFM engines, where cylinder 2 doesn't deactivate. It's a possibility on the 2021+ L87.
• Ignoring injector circuit codes. P0264/P0265 with P0302 on an LGX points to a harness chafe GM has documented.

Frequently Asked Questions

Why does my XT5 only misfire on cylinder 2 after cruising?

On the LGX, cylinder 2 shuts off in V4 mode. GM's 21-NA-036 describes misfires that start after an AFM event, caused by a leaking AFM oil control solenoid or rockers that don't relatch.

Can I swap the AFM solenoids myself?

GM's PIP5824D swap test moves the two solenoids between the cam covers. It's a simple check if you're comfortable working on the engine, but the follow-up rocker inspection needs the cam cover off and careful work.

Does P0302 on a 2017 ATS mean a new engine?

No. GM's bulletins for these AFM-cylinder misfires call for a solenoid, or rockers and lash adjusters on one cylinder, not an engine.

What do P0264 and P0265 have to do with P0302?

They're cylinder 2 injector circuit codes. On 2016 ATS/CTS and 2017 XT5 LGX engines, GM found the #2 injector harness rubbing on the water outlet bolt boss (PIP5386A).

Is cylinder 2 on the front or back of my XT6?

On the transverse XT6, bank 2 (cylinders 2-4-6) is the front, radiator-side bank, and cylinder 2 is at the belt end.

Can disabling AFM fix P0302?

It may hide the symptom, but GM's fix is the faulty solenoid or rockers. A mechanical fault on that cylinder is still there.