OBD2 Diagnostic Code
P0345
Camshaft Position Sensor Circuit Malfunction (Bank 2) — Symptoms & Fix
P0345 points to a signal problem on one specific sensor — not necessarily a failed sensor. Before you replace anything, read this. Wiring issues and dirty connectors account for a large share of P0345 cases, and fixing them costs almost nothing.
Severity
8 / 10
High. Engine stall risk is real. Do not ignore this code.
Safe to Drive?
No — Get It Checked
The engine can stall without warning. Avoid highway driving until this is resolved.
Typical DIY Fix Cost
Low – Moderate
Connector cleaning and wiring inspection cost nothing. Sensor replacement is inexpensive on most vehicles.
🔍 What This Code Means
Your engine computer (ECM) needs to know the exact position of every camshaft at every moment — that is how it decides precisely when to fire each injector and spark plug. The camshaft position sensor (CMP sensor) makes this possible by reading a toothed reluctor wheel on the camshaft and sending a reference signal back to the ECM.
P0345 means the ECM detected a problem in the circuit for the Bank 2 camshaft position sensor — specifically Sensor A, which refers to the intake camshaft. The signal it expected either never arrived, arrived out of range, or was erratic enough that the computer flagged it as unreliable.
💡 Bank 2 is the side of the engine that does not contain cylinder #1. On most front-wheel-drive V6 engines Bank 2 is the rear bank (firewall side). On rear-wheel-drive V8s it is typically the passenger side. P0345 only appears on engines with two cylinder banks — you will never see it on a 4-cylinder.
The word "circuit" in the code definition is important. It means the fault could be the sensor itself, the wiring, the connector, the reluctor wheel, or in rarer cases the timing chain. This is a diagnostic starting point, not an automatic part replacement order.
⚡ Common Symptoms
P0345 can present subtly at first, then get dramatically worse as the sensor signal degrades further. Here is what to watch for.
Check engine light
Usually the first and only sign on mildly affected vehicles. The ECM stores the fault and illuminates the MIL on the first or second failed drive cycle.
Hard start or no-start
Without a valid cam position signal the ECM cannot calculate injection timing. Cold mornings or restarts after the engine has soaked are when this shows up most.
Engine stall at idle
The engine may cut out unexpectedly at a stop sign or traffic light. This is the most serious symptom and the main reason P0345 should not be ignored.
Rough idle and misfires
Incorrect cam timing data causes injectors to fire at the wrong moment on Bank 2 cylinders, producing a noticeable shake or cylinder misfire codes alongside P0345.
Reduced power and hesitation
The ECM often enters a limp or protective mode when cam data is unreliable, pulling timing and fuel delivery back to protect the engine at the expense of performance.
Poor fuel economy
When variable valve timing systems (VVT/CVVT) lose accurate cam position feedback they default to conservative, less efficient timing maps — fuel mileage drops noticeably.
🎯 Most Likely Causes
Listed from most common to least common. Always start at #1. Most P0345 cases are resolved without replacing the sensor at all.
1
Damaged, corroded, or loose connector at the CMP sensorThe sensor connector on Bank 2 sits close to heat sources and moving parts. Oil contamination, road debris, and vibration cause the locking tab to release and the terminal pins to corrode. A poor electrical connection produces an intermittent signal that looks exactly like a failed sensor to the ECM.
~ 35% of cases
2
Chafed, broken, or shorted wiring harnessThe three-wire harness running to the CMP sensor (power, ground, signal) runs through tight routing paths and can wear through on metal edges, zip ties, or engine brackets over time. A single broken signal wire produces the same code as a dead sensor.
~ 28% of cases
3
Failed camshaft position sensor (Bank 2)The sensor itself uses a Hall-effect or magnetic reluctance element that can fail from heat cycling, oil intrusion, or age. Internal failure produces a flat or absent signal. This is the correct diagnosis after wiring and connector checks have been completed — not before.
~ 20% of cases
4
Reluctor wheel damage or debris on the wheelThe toothed ring on the camshaft that the sensor reads can accumulate metal filings or sludge, or suffer a chipped or bent tooth from timing chain debris. A damaged tooth produces a missing pulse in the signal pattern that the ECM interprets as a circuit fault.
~ 10% of cases
5
Stretched timing chain or worn tensionerA worn timing chain allows the camshaft to slip relative to its expected position. This does not break the sensor circuit, but the signal arrives outside the timing window the ECM expects, triggering a correlation fault that stores as P0345 — often alongside P0017 or P0019.
~ 5% of cases
6
ECM fault or software issueIn rare cases the module itself misreads a valid sensor signal. This is a diagnosis of exclusion — only consider it after every component in the circuit has been verified as good. Some manufacturers have issued TSBs and software updates that address false P0345 stores on specific models.
~ 2% of cases
🔧 What to Check First
These three checks take about 25 minutes, require no special tools, and solve P0345 in a significant number of cases before you ever buy a part.
1
Inspect the sensor connector and wiring harnessLocate the Bank 2 camshaft position sensor — on most V6 and V8 engines it sits near the top of the rear cylinder head, close to the firewall. Disconnect the connector and look inside with a flashlight. Check for green or white corrosion on the pins, pushed-back terminals, or oil contamination. Then trace the harness back toward the ECM looking for any spot where the insulation has worn through. Gently tug each wire at the connector — a broken wire inside intact insulation will feel loose. Clean corroded pins with electrical contact cleaner and a small brush before reassembling.
2
Check the sensor air gap and mountingThe CMP sensor must sit within a specific distance from the reluctor wheel — typically 0.020 to 0.060 inches (0.5 to 1.5 mm) depending on the vehicle. Remove the single mounting bolt and pull the sensor out. Look at the tip for metal debris or sludge buildup that would push the sensor away from the wheel. Wipe the tip clean with a lint-free cloth and a small amount of brake cleaner. Reinstall and verify the bolt is snug — a loose sensor can rock enough to produce an intermittent signal.
3
Verify power and ground at the connector with a multimeterDisconnect the sensor connector. Turn the ignition to ON (engine off). The CMP sensor has three wires: reference voltage, ground, and signal. Probe the reference wire against chassis ground — most CMP sensors use a 5V reference from the ECM, so you should read 4.8–5.2V. Then probe the ground wire to chassis ground and confirm near-zero resistance. If reference voltage is missing, the fault is upstream in the harness or ECM — replacing the sensor will not fix it. If both power and ground are good but the code returns after a new sensor, recheck the signal wire for continuity all the way back to the ECM connector pin.
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⚠️ Common Misdiagnosis
P0345 has a reputation for leading to expensive unnecessary repairs. These are the three most common mistakes people make — and how to avoid them.
⚠ Misdiagnosis #1 — Replacing the sensor before inspecting the wiring
The code says "circuit malfunction" — and it means it. A sensor replacement without a prior wiring inspection is guesswork. If the harness is chafed at a bracket and the new sensor is plugged into the same damaged circuit, the code returns the next day. Wiring inspection takes 10 minutes and costs nothing. Always do it first.
Potential savings: Sensor cost plus repeat labor
⚠ Misdiagnosis #2 — Assuming a timing chain job when no timing codes are present
A timing chain job is a significant repair — sometimes requiring partial engine disassembly. If P0345 appears alone with no P0016, P0017, P0018, or P0019 alongside it, there is no correlation fault and the cam timing is likely within spec. A stretched chain almost always sets a correlation code first. If you only have P0345, start with the circuit — not the timing chain.
Potential savings: Hundreds of dollars in unnecessary labor
⚠ Misdiagnosis #3 — Replacing the CMP sensor when the crankshaft position sensor is the real problem
The ECM cross-references the cam signal against the crankshaft position (CKP) sensor to calculate valve timing. A failing crankshaft sensor can produce false cam correlation data that stores as P0345 even though the cam sensor is fine. If the cam sensor and wiring check out clean, test the CKP sensor on the same bank before authorizing any further cam-side repairs.
Potential savings: Avoids replacing the wrong sensor entirely
💰 Estimated Repair Cost
DIY cost = parts only. Shop cost = parts plus labor. Ranges vary by vehicle, region, and shop rate. Bank 2 sensor access is harder on some engines — labor time varies significantly by model.
Connector cleaning and reseating
DIYFree
ShopVery Low
LevelVery Easy
Wiring harness repair (single wire)
DIYVery Low
ShopLow–Moderate
LevelEasy–Moderate
Camshaft position sensor (Bank 2)
DIYLow
ShopLow–Moderate
LevelEasy
Crankshaft position sensor (cross-check)
DIYLow
ShopModerate
LevelModerate
Reluctor wheel cleaning / inspection
DIYVery Low
ShopModerate
LevelModerate
Timing chain and tensioner replacement
DIYHigh
ShopVery High
LevelAdvanced
✅ The majority of P0345 cases are solved with a connector cleaning or a sensor replacement — both inexpensive fixes. A timing chain job is rarely needed and only appropriate when correlation codes are also present.
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🚗 Most Reported On
P0345 is exclusive to multi-bank engines. These vehicles account for the highest share of verified P0345 reports based on owner data and shop records.
Ford F-150 (2004–2010, 5.4L 3-valve)
Nissan Maxima (2004–2008, 3.5L VQ35DE)
Infiniti G35 / G37 (2003–2013, VQ35 / VQ37)
Nissan Altima (2007–2012, 3.5L V6)
Ford Mustang (2005–2010, 4.6L / 5.4L)
Nissan Pathfinder (2005–2012, 4.0L VQ40DE)
Ford Explorer (2002–2010, 4.6L V8)
Infiniti FX35 / FX45 (2003–2008)
❓ Frequently Asked Questions
Can I drive with P0345 active?
Short distances only — to a nearby shop is manageable. P0345 can cause the engine to stall without warning, which is a safety risk. The ECM may also cut fuel injection to protect the engine. Do not ignore this code or drive on the highway with it active.
Why does P0345 come back after I clear it?
Clearing the code removes the warning light, not the fault. If the underlying cause — a faulty sensor, a wiring problem, or a timing issue — has not been fixed, the ECM will detect the same circuit fault within one drive cycle and set the code again.
What is the difference between P0345 and P0340?
P0340 covers the camshaft position sensor circuit on Bank 1. P0345 is the same fault on Bank 2 — the opposite bank of a V6 or V8 engine. On a 4-cylinder engine you will only ever see P0340, never P0345, because there is only one bank.
Can a bad timing chain cause P0345?
Yes. A stretched timing chain or worn timing chain tensioner causes the camshaft to slip out of its expected position. The ECM compares camshaft and crankshaft signals — when the timing relationship drifts, it flags a circuit fault. If P0345 appears alongside P0016 or P0017, timing chain wear is the likely cause.
How do I know if it is the sensor or the wiring?
Start by inspecting the connector and harness for damage, corrosion, or chafing. Then measure supply voltage at the sensor connector — you should see a 5V reference, a ground, and a signal wire. If power and ground are present but the signal is absent or erratic, the sensor itself is the most likely failure. A digital multimeter and a wiring diagram for your specific vehicle are essential at this stage.
🔗 Related Codes
These codes share overlapping causes or commonly appear alongside P0345 — especially on VVT-equipped engines.
This guide is for informational purposes only. Always consult a qualified mechanic before performing any vehicle repair. OBDPlatform is not responsible for actions taken based on this content.