P0341 on 2013-2016 Scion FR-S: Camshaft Sensor Causes and Fixes

What's Unique About the 2013-2016 Scion FR-S

The Scion FR-S, a joint project with Subaru, has a known and documented issue causing P0341, particularly on early 2013 models. A Technical Service Bulletin (TSB S-SB-0013-14 for Scion, 11-130-13R for Subaru) was issued because the air gap between the camshaft position sensor and the camshaft's reluctor plate can be out of specification due to irregular stamping of the plate from the factory. This means the fix is often not a new sensor, but rather the simple installation of a specific shim to correct the clearance. Ignoring this specific issue on vehicles produced before VIN JF1ZAA1#D#721474 can lead to unnecessary parts replacement.

Symptoms You May Notice

• Check Engine Light is on
• Difficulty starting the engine, or extended cranking time
• Rough or uneven idle
• Engine stalling, especially at low speeds or when coming to a stop
• Noticeable loss of engine power and hesitation when accelerating
• Engine misfires (may be accompanied by P030x codes)
• Vehicle enters 'limp mode' with severely reduced power

Most Likely Causes

1. Incorrect Camshaft Position Sensor Clearance 🔴 High Probability → Shop Engine Camshaft Position Sensor A known manufacturing tolerance issue on early production 2013 vehicles, specifically addressed by Scion/Toyota TSB S-SB-0013-14 and Subaru TSB 11-130-13R.
   How to confirm: Follow the TSB procedure to remove the sensor and measure the air gap. The TSB applies to vehicles produced before VIN JF1ZAA1#D#721474. The specified clearance is 1.25 to 1.35 mm.
   Typical fix: If the clearance is out of spec, install the correct shim from the Repair Part Set (P/N: SU003-04600). Do not stack shims.
   Est. part cost: $10-$30 for the shim kit.
2. Faulty Camshaft Position Sensor 🟡 Medium Probability → Shop Engine Camshaft Position Sensor Sensors can fail over time due to heat cycles and internal electronic wear. This is the next logical cause after ruling out the clearance issue.
   How to confirm: After confirming sensor clearance is correct, swap the Bank 1 intake sensor with the Bank 2 (driver's side) intake sensor. Clear codes and drive. If the code changes to P0346 (Bank 2 Intake), the sensor is bad.
   Typical fix: Replace the faulty camshaft position sensor (Bank 1, Intake).
   Est. part cost: $90-$150 for OEM, $40-$80 for aftermarket.
3. Damaged Wiring or Connector ⚪ Low Probability Connectors can become brittle from heat, and wiring can be damaged during other engine work, such as the valve spring recall service.
   How to confirm: Visually inspect the sensor's wiring harness and connector for signs of corrosion, oil contamination, loose pins, or physical damage. Use a multimeter to check for proper voltage (~5V reference), ground, and signal at the connector.
   Typical fix: Clean the connector with electrical contact cleaner or repair/replace the damaged section of the wiring harness.
   Est. part cost: $5-$50 for cleaning supplies or a new pigtail connector.

Rare But Worth Checking

• Failing VVT Intake Sprocket (Cam Phaser): In some cases, particularly when the P0341 code appears only during cold starts and other fixes fail, the issue may be a mechanically failing VVT intake sprocket. Forum users have reported that after replacing sensors and checking wiring, replacing the sprocket was the final solution. This is a more complex and expensive repair.
• Stretched Timing Chain or Failed Tensioner: → Shop Engine Timing Chain While uncommon, a stretched timing chain or a failing tensioner can cause the cam and crank signals to de-synchronize, triggering a performance code like P0341. This is a significant mechanical issue often accompanied by rattling noises, and may be linked to improper service during other repairs.
• Improper Reassembly After Valve Spring Recall (NHTSA 18V-727 / J02): Many 2013 models were subject to a major valve spring recall. If timing components were not reassembled correctly, or if other parts like a timing chain tensioner were damaged during this intensive service, it could lead to various timing-related codes, including P0341. Some owners have reported P0341 issues appearing after the recall service was performed.

Diagnosis Steps

1. Scan the ECM for trouble codes and confirm P0341 is present. Note any other codes.
2. If the vehicle is a 2013 model, check if TSB S-SB-0013-14 applies by checking the VIN. The TSB applies to vehicles produced before VIN JF1ZAA1#D#721474.
3. Inspect the Bank 1 (passenger side) intake camshaft position sensor and its connector for any obvious damage, corrosion, or loose connections.
4. Following the TSB, remove the sensor and use a feeler gauge to measure the air gap. If it's out of spec (spec is 1.25-1.35mm), install the correct shim from kit SU003-04600. Clear codes and test drive.
5. If the clearance is correct or the TSB does not apply, swap the Bank 1 intake sensor with the Bank 2 (driver's side) intake sensor. Clear the codes and drive the vehicle. If the code returns as P0346 (for Bank 2), the sensor you moved is faulty and needs replacement.
6. If the code remains P0341 after the swap, the problem is likely in the wiring or a deeper mechanical issue.
7. Using a multimeter, test the sensor connector for proper voltage (5V reference), ground, and signal integrity.
8. If all sensor and wiring tests pass, especially if the code appears only on cold starts, the issue may be with the VVT intake sprocket or timing chain, which requires more advanced mechanical diagnosis.

Parts You'll Likely Need

• Camshaft Position Sensor Shim Kit (OEM #SU003-04600) — Required to fix the incorrect sensor air gap, which is the most common cause of P0341 on 2013 models as per TSB S-SB-0013-14. This is the 'Repair Part Set' referenced in the TSB.
  Trusted brands: Toyota/Scion/Subaru Genuine Parts
  OEM price range: $10-$30
• Intake Camshaft Position Sensor (Bank 1) (OEM #SU003-04294 (may be superseded by SU003-00186)) — This sensor is the primary source of the fault signal if the clearance is correct but the sensor has failed electronically.
  Trusted brands: Denso (OEM), Hitachi, NTK
  OEM price range: $90-$150
  Aftermarket price range: $40-$80
• VVT Intake Camshaft Sprocket (Bank 1) (OEM #SU003-11391) — In rare cases where the sensor and wiring are good, a failing VVT sprocket can be the root cause, especially if the code appears only on cold starts.
  Trusted brands: Toyota/Scion/Subaru Genuine Parts
  OEM price range: $200-$300

Related Codes That Often Appear With This One

• P0340 — This is a general circuit malfunction code for the same sensor. A failing sensor, wiring issue, or the TSB-related clearance issue can trigger both codes.
• P0301, P0302, P0303, P0304 — These are misfire codes for individual cylinders. Incorrect camshaft timing information directly disrupts ignition timing, leading to misfires. The TSB for the sensor clearance issue explicitly lists these as potential companion codes.
• P0016 — This code indicates a 'Crankshaft/Camshaft Position Correlation' error for Bank 1 Sensor A. It often points to a more significant mechanical timing issue (like a jumped tooth or stretched chain) but can also be triggered by the same sensor clearance or sensor fault as P0341.
• P0345, P0346, P0365, P0366, P0390, P0391 — These are the codes for the other three camshaft sensors. The TSB for the clearance issue notes that any of these codes can be caused by the same manufacturing problem at their respective locations.

Technical Service Bulletins (TSBs) & Recalls

• S-SB-0013-14: Addresses intake/exhaust camshaft position sensor and misfire DTCs due to sensor clearance being out of specification on 2013 FR-S models produced before VIN JF1ZAA1#D#721474.
• S-SB-0033-13: The original, superseded version of the TSB for the same issue.
• Subaru TSB 11-130-13R: The equivalent bulletin for the 2013 Subaru BRZ, covering the same clearance issue and repair procedure.

Platform-Specific Known Issues

• Early production 2013 models are prone to incorrect camshaft position sensor clearance, which is addressed by TSB S-SB-0013-14 (which superseded S-SB-0033-13).
• The Subaru equivalent TSB for the 2013 BRZ is 11-130-13R, detailing the same issue.
• Symptoms can overlap with the NHTSA 18V-727 (Toyota J02) valve spring recall, which also affects 2013 models and can cause stalling and rough running.

Mechanic-Grade Diagnostic Values

• Camshaft Position Sensor Connector Voltage (Key On, Engine Off) — expected: Pin 1 (Gray Wire): ~5V DC Reference. Pin 2 (Green Wire): ~4-5V DC Signal. Pin 3 (Brown Wire): Near 0V (Good continuity to ground).. Failure: No voltage on Pin 1 suggests a power supply issue from the ECM or a blown fuse. No voltage on Pin 2 could be an ECM or wiring fault. Voltage significantly above 0V on Pin 3 indicates a bad ground connection.
• Camshaft Position Sensor Signal Waveform (Engine Running) — expected: A clean digital square wave alternating between approximately 0V and 5V when viewed with an oscilloscope.. Failure: A missing, erratic, distorted, or noisy waveform indicates a faulty sensor, a problem with the reluctor wheel on the camshaft, or wiring interference.
• Camshaft Position Sensor Retaining Bolt Torque — expected: 6.4 Nm (4.7 ft-lbs).. Failure: Over-torquing can damage the sensor housing; under-torquing can allow the sensor to vibrate or move, affecting the signal.

Scan Tool Commands That Help

• Toyota Techstream: VVT Active Test — Use this bidirectional command when the TSB shim and sensor swap do not fix the code, especially if symptoms occur only on cold starts. It allows you to command the VVT intake sprocket (cam phaser) to advance. A failure to respond, or an engine stall on the problem bank (but not the good bank), points strongly to a mechanical fault in the VVT sprocket or its oil control valve.
• Toyota Techstream: Learning Value Reset — This function may be required after replacing VVT components or the ECM to clear learned adaptations and ensure the system operates from a clean baseline.

Wiring & Ground Locations

• Bank 1 Intake Cam Sensor Connector — The upper sensor on the front of the engine, passenger side.. This is the primary connector to test for power, ground, and signal for code P0341. The pins are: Pin 1 (Gray) = 5V Power, Pin 2 (Green) = Signal, Pin 3 (Brown) = Ground.
• Main Engine Grounds — There are three key ground straps: 1) Bottom-front of the engine to the frame rail (driver side), 2) Bottom-front of the engine to the frame rail (passenger side), 3) Top-rear of the engine/transmission (passenger side) to the transmission tunnel.. A poor engine ground can introduce electrical noise or voltage offsets, causing the sensor's signal to fall out of its expected range and trigger a P0341 performance code, even if the sensor and its direct wiring are good.
• ECM (Engine Control Module) — Located at the right end of the dash, accessible from the passenger footwell.. This is the termination point for the sensor's wiring. In rare cases of persistent wiring faults, continuity and resistance checks must be performed from the sensor connector back to the corresponding pins at the ECM.

Real Owner Repair Stories

• FT86Club forum user 'DoubleV' (2013 Toyota GT86 (equivalent to Scion FR-S)) — P0341 code would only appear on a cold start. After the engine warmed up to ~200°F, the code could be cleared and would not return during normal driving.
  ❌ Tried (didn't work) Replacing the Bank 1 intake camshaft position sensor., Replacing the Bank 1 intake Oil Control Valve (OCV)., Checking wiring and voltages., Having the valve spring recall performed (which introduced separate timing tensioner issues that were also fixed).
  ✅ What actually fixed it The Bank 1 intake VVT sprocket was faulty. After swapping it with a known-good sprocket from another car, the cold start P0341 issue was resolved.

OEM Part Supersession History

• Various early 2012-2013 VVT Sprockets → Multiple updated part numbers — The VVT sprockets for the FA20 engine were updated at least twice after their initial 2012 release to improve reliability and prevent failures.
  Heads up: While mechanically interchangeable, using an older, original-spec sprocket as a replacement is not advised due to the known reliability issues. Always source the latest available part number.

Model Year Variations Within This Range

• 2013 only: Vehicles produced before VIN JF1ZAA1#D#721474 are subject to TSB S-SB-0013-14 for incorrect cam sensor clearance. Later models are not affected by this specific manufacturing issue.
• 2014: The 2014 model year introduced valvetrain updates, including longer valve stems and revised rocker arms with deeper pockets to improve rocker arm retention.
• 2015-2016: The 2015 model year received an updated engine sub-harness and different coil packs. This can create compatibility issues when swapping a 2015+ engine into a 2013-2014 car, potentially requiring re-pinning of connectors.

Diagnostic Flowchart

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0346 — Camshaft Position Sensor 'A' Circuit Range/Performance (Bank 2). This code will appear if you swap a faulty Bank 1 intake sensor to the Bank 2 position during diagnosis.
• P0300 — Random/Multiple Cylinder Misfire Detected. Often accompanies P0341 on early 2013 models due to the camshaft position sensor clearance issue addressed in TSB S-SB-0013-14.
• P0340 — Camshaft Position Sensor 'A' Circuit. Frequently appears alongside P0341 when there is a complete loss of signal, wiring damage, or severe sensor failure.
• P0365 — Camshaft Position Sensor 'B' Circuit (Bank 1). Shares the same wiring harness routing and can be triggered simultaneously if the harness is damaged during engine work like the valve spring recall.
• P0366 — Camshaft Position Sensor 'B' Circuit Range/Performance (Bank 1). Related to the exhaust camshaft sensor on the same bank, often seen together with P0341 during no-start conditions or timing chain issues.

Frequently Asked Questions