P0016 Code on a GMC: Crankshaft–Intake Camshaft Correlation, Bank 1 (GMC Guide)

P0016 on a GMC is "Crankshaft Position – Camshaft Position Correlation, Bank 1 Sensor A." The engine control module (ECM) checked where the bank 1 intake cam signal lands against the crankshaft signal, with the cam phaser parked, and found it outside GM's window. That makes it a base mechanical timing code — and on a 2007–2012 Acadia or a 2010–2012 Terrain V6 it is often the first sign of stretched timing chains. But GM's GMC bulletins tell a much wider story: a crankshaft reluctor that slid on a 2012–2013 Yukon or Sierra V8, a cam reluctor that spun on a Terrain 2.4L that is timed perfectly, sticking park-lock valves on a 2017-on Acadia or Canyon 3.6L, and two identical connectors swapped during an engine repair on a Canyon. On a 2023–2024 Sierra 1500 or Yukon, GM even pushed out software so the dash spells out a warning when P0016 sets.

What Does P0016 Mean on a GMC?

The crankshaft position sensor reads a toothed reluctor on the crankshaft; the cam position sensor reads a reluctor on the camshaft. Because a chain ties the two shafts together, every cam pulse should arrive at a predictable crank angle. P0016 sets when it does not.

GM's 2019 OBD summary tables for the Gen V V8 group (the section that covers the L84 5.3L in the new Sierra 1500) spell out the test: P0016 fails when the bank 1 cam sensor pulse arrives more than 11.0 crank degrees early or late, judged as 2 failures out of 3 tests, and it is a Type A, one-trip code — the check engine light comes on the first time it fails. GM's 2015 tables for the 3.6L V6 use a window of roughly 9 crank degrees early to 12 late, also two trips.

Every version carries the same enable condition: the cam phaser must be "parked." That is why P0016 is about the chain, sprockets and reluctor wheels rather than the phaser's normal movement — and why a phaser that will not return to park can still set it. The test also will not run while P0340 or P0341 (cam sensor faults) are active, so a dead cam sensor normally sets those codes, not P0016.

"Sensor A" is the intake cam on overhead-cam engines. A pushrod V8 or 4.3L has one camshaft, so on a Sierra, Yukon or Savana P0016 simply means the cam is out of place. On the transverse 3.6L in the Acadia and Terrain, bank 1 is the rear bank, toward the firewall; the front bank's intake cam reports as P0018.

Which GMCs Set P0016

We matched GM's bulletins to GMC models and engines:

• First-generation 3.6L/3.0L V6 (LY7, LLT, LF1, LFW, LFX): 2007–2016 Acadia, 2010–2017 Terrain V6, 2015–2016 Canyon 3.6L.
• Second-generation 3.6L (LGX, LGZ): 2017-on Acadia, 2017-on Canyon.
• 2.4L four-cylinder (LAF, LEA): 2010–2016 Terrain.
• Small-block V8s and the 4.3L: 2012–2013 Sierra, Yukon and Savana (Gen IV), 2014-on Sierra 1500 and 2015-on Yukon (Gen V), 2021–2024 Yukon and 2023–2024 Sierra 1500.
• 2002–2004 Envoy 4.2L LL8: GM index entries 01623, 00156A and 3659A name "P0016 or P1345." On a 2002–2003 Envoy, GM's tables list this fault as P1345 — see our P1345 GMC guide.

The 2004–2012 Canyon's Atlas engines phase only the exhaust cam, and their GM bulletins name P0017. Check the engine RPO code on your parts label first — the right GM document depends on it.

Acadia and Terrain V6: Chains and Reluctors

On a 2007–2012 Acadia, P0016 usually arrives with P0008, P0017, P0018 or P0019. That cluster is GM's classic stretched-chain signature, and GM bulletin 12-06-01-009F names the 2007–2012 Acadia (LY7, LLT) and the 2010–2012 Terrain (LF1, LFW) directly.

The bulletin's most important line is a warning: GM's chain kits deliberately leave out the idler sprockets, cam actuator gears, crankshaft gear and guides, because those parts "are being replaced unnecessarily and are not worn." Guides are replaced only when the wear block is worn through into the base friction material. GM's kit numbers for the Acadia are 12650230 (2007 LY7), 12650231 (2008 LY7) and 12651450 (2009–2012 LLT). The kit lists we read do not name the Terrain, so have the parts department pull the kit by VIN.

GM's labor times in that bulletin show what the job is: 9.5 hours on a FWD Acadia, 9.7 hours AWD, and 8.7 hours on a 2010–2012 Terrain. The bulletin also adds camshaft thrust washers on cylinder heads built before June 5, 2009, PCV and cam-cover parts on 2007–2011 Acadias, and an Oil Life Monitor calibration update — GM's acknowledgement that oil change intervals were part of the chain-wear story.

Before anyone quotes chains, GM's PIP3423P adds a twist. It covers the 2007–2017 Acadia (LLT, LY7), 2010–2017 Terrain (LF1, LFW, LFX) and 2015–2016 Canyon (LFX). If the chains and tensioners are tight and service information finds nothing, the crankshaft sensor reluctor pressed onto the rear of the crankshaft may have moved. A good reluctor measures 25–26 mm from the end of the machined crank throw to the gap in the reluctor, and GM notes that on some applications you can check it with a borescope through the crank sensor hole without removing the oil pan. If it has moved, the fix is a crankshaft — a chain kit will not clear the code.

2017-on Acadia and Canyon 3.6L

The second-generation 3.6L tells a different story, and GM has two GMC documents on it.

PIP5730B covers the 2017–2021 Acadia (LGX) and 2017–2021 Canyon (LGZ) with P0011, P0016, P0018 or P0021, "usually" with no other drivability concern. GM's cause is the intake camshaft position actuator park lock solenoid valves sticking, or coming apart with part of the valve stuck in the actuator. GM says plainly that normal diagnosis does not lead a technician to these valves. The procedure: remove and inspect them; if nothing is visibly wrong and only one bank sets codes, swap them bank to bank and see whether the code follows. If they are bad, replace both.

23-NA-091 (replacing 19-NA-150 and PIP5571A) covers the 2017–2023 Acadia (LGX) and 2017–2019 Canyon (LGZ): a hard P0016 and/or P0018 with a rough idle after an engine repair that moved the harness on the right front of the engine. The bank 1 intake actuator solenoid connector on top of the engine and the bank 1 park-lock solenoid connector at the front are identical and can be told apart only by wire color — and they get swapped. Plug them back in correctly and clear the code.

Terrain 2.4L: The Spun Cam Reluctor

GM's PIP4548F is titled "MIL On With DTC P0016 And/Or P0017 Setting On A Properly Timed Engine Or Crank No Start," and it names the 2010–2016 Terrain with the 2.4L. The cam reluctor is a press fit with no key; GM says an overheat can let it spin on the camshaft when hot. Spin far enough and the engine cranks but will not start. The reluctor cannot be repositioned, so the fix is a camshaft — which comes with the reluctor already pressed on in the right place.

On the 2010 Terrain, GM's PIP4716F adds a sharp startup rattle that may set P0011, P0014, P0016 or P0017 — check the accessory belt and pulley before cam actuators. And GM's oil consumption bulletin 13-06-01-003H for the 2010–2013 Terrain 2.4L notes the dipstick shows no oil until about 1.25 quarts low — a phaser-starving condition worth ruling out.

Sierra, Yukon and Savana V8s

GM has three GMC truck documents on P0016, and none of them is about a worn chain:

• PIP5102 covers 2012–2013 Sierra, Yukon and Savana with the L20, L9H, L94, LC9 and LMG V8s built between February 1, 2012 and February 12, 2013. P0016 and/or a crank-no-start "with no issue with the phaser or the wiring" can mean the crankshaft reluctor has moved. GM's fix is a crankshaft.
• PIP5554A covers the 2014–2019 Sierra 1500 (4.3L, 5.3L, 6.2L) and 2015–2019 Yukon (L83, L86) with P0016 after internal engine repair. GM's cause: base timing not set correctly, because the timing marks are hard to see straight on and an off-center oil feed hole in the block throws off the eye. GM's tip is to mark the teeth 180 degrees from the timing marks and count chain links to use the chain itself as the alignment guide.
• Service Update N252510320 (September 2025) covers the 2023–2024 Sierra 1500, Yukon and Yukon XL: an ECM reprogram, by dealer or over-the-air, that adds a Driver Information Center warning message to the check engine light if P0016 sets. No parts are involved; it changes how clearly the truck warns you.

If a Sierra or Yukon has P0011 rather than P0016, that is the phaser performance code; see our P0011 GMC guide.

Symptoms of P0016 on a GMC

• Check engine light, often with no running complaint (park-lock valves on a 2017-on Acadia or Canyon)
• A few seconds of rattle after a cold start (chain stretch on a first-generation Acadia or Terrain V6)
• Rough idle right after engine work (swapped connectors on a Canyon or Acadia 3.6L; base timing on a Gen V V8)
• Long crank or crank-no-start (spun cam reluctor on a Terrain 2.4L; moved crank reluctor on a 2012–2013 V8)
• P0008, P0017, P0018 or P0019 stored alongside on the first-generation 3.6L

Causes and How to Confirm Each

How Is P0016 Diagnosed on a GMC?

1. Identify the engine RPO. A Gen V Sierra, a 2010 Terrain 2.4L and a 2018 Acadia 3.6L follow completely different GM documents.
2. Record every cam and crank code and whether each is current or history. A cluster on a first-generation V6 points at chains; a lone P0016 needs more evidence.
3. Ask what work was done recently. P0016 after engine work sends you to 23-NA-091 (3.6L) or PIP5554A (Gen V V8) first.
4. Check oil level and condition. On a Terrain 2.4L, remember the dipstick can read empty only at about 1.25 quarts low.
5. Read cam/crank variation data on a GM-capable scan tool and compare it to the service limit. Listen for rattle at a cold start.
6. Check the engine-specific GM item before buying a chain kit: park-lock valves on the LGX/LGZ, the cam reluctor on the 2.4L, the crank reluctor on the HFV6 and 2012–2013 V8s.
7. If chains are replaced on an Acadia or Terrain V6, follow 12-06-01-009F — kit only, guides only if worn through, thrust washers and the Oil Life Monitor update where they apply.

Parts and Cost

GM Documents That Name P0016 on GMC Models

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

What Other P0016 Pages Get Wrong

• "P0016 means a timing chain." GM's GMC documents cover moved crank reluctors, a spun cam reluctor, sticking park-lock valves, swapped connectors and mis-set base timing — all setting P0016 with a healthy chain.
• "Replace the cam sensor." GM's P0016 test does not run while the cam sensor codes P0340 or P0341 are active. P0016 is a correlation code.
• "Replace every guide and sprocket." GM's own chain bulletin for the Acadia and Terrain says those parts are being replaced unnecessarily.
• Ignoring recent engine work. Two GMC documents are about P0016 created by the repair itself.
• Treating every GMC alike. A 2002–2003 Envoy reports this fault as P1345. For the same code on a Chevy, see our P0016 Chevy Equinox guide.

Frequently Asked Questions

Is P0016 serious on a GMC Acadia?

It can be. On a 2007–2012 Acadia it often means chain wear, which only gets worse, and GM's labor time for the chain job is 9.5–9.7 hours. Have the cam/crank variation data checked rather than driving on it indefinitely.

Does P0016 on a 2018 Acadia or Canyon mean the chain is stretched?

Not necessarily. GM's PIP5730B blames sticking intake park lock solenoid valves on the 2017–2021 Acadia and Canyon 3.6L, usually with no drivability symptom. If the engine was just repaired, 23-NA-091 points to two swapped connectors.

Can a Terrain 2.4L set P0016 with good timing?

Yes. GM's PIP4548F covers exactly that on the 2010–2016 Terrain: the press-fit cam reluctor can spin on the camshaft, and the fix is a camshaft.

Why does my 2024 Sierra show a message for P0016?

GM's Service Update N252510320 reprograms the ECM on 2023–2024 Sierra 1500, Yukon and Yukon XL trucks to add a Driver Information Center warning when P0016 sets. The message is new; the code still needs diagnosis.

My Sierra set P0016 right after a timing chain job. What happened?

GM's PIP5554A describes P0016 after internal repairs on 2014–2019 Sierra 1500 and 2015–2019 Yukon engines because base timing was not set correctly. GM recommends marking the teeth opposite the timing marks and using the chain links as the guide.

Does a 2002 Envoy use P0016?

GM's 2002 and 2003 OBD tables for the 4.2L LL8 list the cam-to-crank correlation error as P1345; the 2004 table lists P0016. GM's Envoy bulletins name both codes together.