P0340 on Nissan: How to Diagnose & Fix

Multiple owners report the Cube stalling unexpectedly while driving at various speeds, including highway speeds. The engine shuts off without warning, causing loss of power steering and power brakes. In some cases, pumping the accelerator at the moment of stalling can catch the engine before it dies completely. The issue has been linked to faulty crankshaft position sensors, throttle body failures, and ECM software bugs.

Altimas in this period frequently suffer from failing crankshaft position sensors and camshaft position sensors, especially on the 2.5L and 3.5L engines. Owners report intermittent stalling at stops or while driving, extended cranking, sudden no-start conditions, and check-engine lights. Nissan issued service information and many owner reports describe repeat failures with cheap aftermarket sensors.

On the 3.5L VQ35DE V6 the plastic secondary timing chain guides/tensioner shoes become brittle and break, and the secondary (cam) chain tensioners lose tension. This produces a loud rattle or whine from the front of the engine, most pronounced for the first few seconds of a cold start. When a guide breaks, the chain runs slack and can contact the tensioner piston (the 'death rattle'), risking valve-timing skip and internal damage if ignored. Owners across multiple Altima forums document this as one of the defining VQ35DE problems, and there is a Nissan TSB covering secondary-chain replacement.

The Crank Angle Sensor (CAS) on the VG30DE and VG30DETT engines is located inside the distributor and is a common failure point on both naturally aspirated and twin turbo Z32 models. The CAS provides timing information to the ECU, and when it fails, the engine will not start or will stall intermittently. The internal optical sensor deteriorates with heat and age. CAS failure is one of the most common reasons for Z32 no-start conditions. Replacement requires distributor removal.

The Z32 uses an optical crank angle sensor built into the distributor at the front of the driver's-side (rear-of-engine) cylinder head. It reads engine speed and crank position via a slotted disc and photodiodes (360 slits plus six 120-degree reference slits). With age the internal LED/photodiode optics degrade, the sealed bearing wears, and the connector corrodes — producing intermittent or total spark/timing signal loss. Because the ECU relies on the CAS for both ignition and injection timing, a failing unit causes hot-restart failures, stalling, and no-starts that are notoriously hard to chase. Many are misdiagnosed when the real fault is corrosion in the harness connector.

The crankshaft position sensor's internal electronics degrade with heat and fail intermittently. As the engine warms the sensor signal drops out, causing the engine to stall and refuse to restart until it cools, then run normally again. It sets P0335/P0336 and is frequently misdiagnosed. Nissan owners report premature failure of cheap aftermarket sensors, so an OEM/Hitachi unit is recommended; on many Sentras the camshaft sensor is replaced alongside it.

The defining electrical failure of the 1990s Sentra. On both the GA16DE (1.6L) and SR20DE (2.0L), the crank angle and camshaft position signals are generated by an OPTICAL sensor (a slotted disc read by an LED/photo-diode) housed inside the distributor. Two age-related failure modes dominate: (1) the internal distributor shaft seal fails and engine oil weeps up into the distributor, coating the optical disc and electronics; and (2) the optical encoder/electronics degrade or the encoder wheel works loose. As the sensor warms with the engine it drops out intermittently, so the classic pattern is an engine that runs, then stalls once hot and refuses to restart until it cools. At high mileage it becomes a hard-crank or no-start. Because the sensor is integral to the distributor, Nissan supplies it only as a complete distributor assembly.

A common failure on B15 Sentras is deterioration of the crankshaft position sensor and, less often, the camshaft position sensor. Owners report sudden stalling while driving, extended cranking, or a hot no-start condition that becomes more frequent over time. Nissan issued service information for engine stall/no-start conditions tied to these sensors, and owner complaints frequently mention the engine cutting out without much warning.

Circuit boards inside the crank position sensor and cam position sensors were built with improper solder joints; heat stress accelerated by flux residue cracks the joint, so the sensor drops out intermittently as it warms up. The engine stalls without warning while driving, or refuses to restart until it cools. Nissan recalled the affected sensors under NHTSA campaign 03V455000, covering 2003 350Z among a very large group of VQ-powered Nissan and Infiniti vehicles built in the affected sensor window, with owner notification beginning December 22, 2003. Beyond the recall population, crank sensor failure remains one of the most common causes of hot-stall on 2003-2006 VQ35DE cars in general — a recall-repaired car can still fail again years later on an aftermarket sensor.

A well-documented failure on first-generation Frontier V6 trucks is the distributor assembly, especially the internal cam/crank angle sensor and bearing wear inside the distributor. Owners report intermittent bucking, random stalling, hard starts, and eventual crank-no-start, often after the engine warms up. Nissan issued service information for distributor-related drivability faults, and owner complaint patterns are consistent across Frontier and related Xterra applications using the VG33E/VG33ER.

The first-model-year 2003 Nissan Murano is included in NHTSA recall 03V455000. On affected vehicles, the circuit board inside the crankshaft position sensor or the camshaft position sensor can have an improper solder joint. Heat stress deforms the solder, and flux residue left behind during manufacturing accelerates the process, so a sensor that worked fine when new can fail later in service. Because the Murano's engine management depends on these signals, the failure shows up as a Service Engine Soon light, a crank-but-no-start, a sudden drop in power, or the engine simply quitting while the vehicle is being driven - which NHTSA notes could result in a crash. The campaign covers about 630,000 vehicles in total across all Nissan and Infiniti models included, not the Murano alone.

The crank and cam position sensors are a well-documented weak point on the 4th-generation VQ30DE Maxima. Internal solder joints and the sensor's electronics degrade with heat and age, producing intermittent or lost signal. This is the same failure mode Nissan later formally recalled on the 2000-2002 cars (NHTSA 03V455000) for improper solder joints; 1995-1999 owners experience identical symptoms without recall coverage. (Note: unlike the earlier VG30 engines, the A32 VQ30DE is distributorless with coil packs; the crank position REF sensor sits near the oil filter, the POS sensor at the rear of the oil pan, and the cam sensor at the front timing cover.)

The V6 Pathfinders of this era use a camshaft-driven Hitachi distributor that houses the optical crank/cam position sensor and rotor inside a single unit. It is one of the most frequently reported failure points on the WD21 (1990-1995 VG30E) and early R50 (1996-1999 VG33E) trucks. Internal wear, a degrading optical disc, a failing internal coil, or the rotor-retaining screw working loose leads to intermittent or complete loss of spark and timing signal. Failures are often heat-related, showing up once the engine is warm and worsening under load.

The 2013-2016 Pathfinder with the 3.5L VQ35DE engine develops timing chain stretch and chain guide wear, typically after 80,000-120,000 miles. The timing chain tensioner, secondary chain tensioners, and plastic chain guides all degrade over time. Stretched chains cause rattling on cold start, timing drift triggering misfire codes, and eventual engine failure if the chain jumps timing. The VQ35DE uses three chains (primary and two secondary), making replacement a complex job requiring 8-12 hours of labor. Infrequent oil changes accelerate chain and guide wear due to inadequate tensioner lubrication.

Both the 3.0L VG30E (1990-1995) and 3.3L VG33E (1996-1999) are timing-belt engines. The belt, tensioner, and idler are service items that harden and wear with age; a failed tensioner bearing produces a ticking or scraping noise from the front of the engine, and a snapped belt leaves the engine cranking but not starting. These VG-series engines are widely documented as interference designs, so a broken belt commonly bends valves and can total the engine. A mid-1993 production change moved the VG30E from square-tooth to round-tooth belt/sprockets, so the correct part must be verified by inspection on 1993-1994 trucks.

The KA24DE uses a camshaft-driven distributor that houses the optical Cam Angle Sensor (CAS) and the integral ignition module. Two age-related problems are common. First, the cap-to-distributor O-ring dries out, cracks, and lets oil weep out from under the cap; separately, a clogged PCV valve raises crankcase pressure and pushes oil up into the distributor internally, where it fouls the optical sensor disc and eventually kills the ignition module. Second, the optical CAS itself degrades. Symptoms range from rough running and stalling to no-start, frequently logging Nissan self-diagnostic Code 11 (crank/cam position signal) and Code 21 (ignition signal). Worn cap and rotor contacts add misfire and hard-start complaints.

The KA24DE's distributor houses the optical crank angle sensor (CAS). The internal optical disc and bearings wear with age, causing intermittent or no-start conditions, often throwing ECU codes 11 (crank angle sensor) and 21 (ignition signal). The distributor O-ring also leaks oil into the unit, accelerating failure. Power transistor failure within the distributor circuit can prematurely kill ignition coils.

The QR25DE 2.5L four-cylinder used in the second-generation (T32) Rogue is prone to timing-chain tensioner wear and chain/guide stretch. Worn plastic guides and a weak tension-side tensioner produce a loud rattle, most noticeable at cold startup and idle. As the chain stretches, valve timing drifts, triggering camshaft/crankshaft correlation faults; if ignored it can progress to chain skip, contact damage, or catastrophic engine failure. Nissan has historically characterized the noise as normal, but owners and independent shops document genuine tensioner/guide failures.

The VK56 timing chain system uses plastic-faced guides and an oil-pressure-fed hydraulic tensioner. The feed passage to the tensioner is very small and gets restricted by sludge or debris on trucks run on stretched oil-change intervals, so the tensioner loses pressure and the chain goes slack. The chain then saws through the guide face and can contact the chain oiler jet, producing a rattle or squeal from the front cover that is loudest for the first seconds after a cold start and under light load. Left alone, guide material breaks off into the pan, timing drifts, and in the worst cases the chain jumps a tooth.