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When your car’s check engine light comes on and you discover the OBD P1340 code, it can cause a wave of confusion and concern. What does it mean? Is your engine in danger? Is this an expensive repair? You’re not alone—many car owners encounter this code without fully understanding what it implies. In this guide, we’ll walk you through everything you need to know about the OBD P1340 trouble code, breaking down complex terms and providing solutions you can act on.
What Is the OBD P1340 Code?
OBD P1340 is a diagnostic trouble code flagged by your vehicle’s engine computer (ECM or PCM). While it’s considered a generic powertrain code (starting with “P”), its specific meaning can differ based on your vehicle’s make and model.
Generic Definition
- At its core, P1340 usually points to a problem with your camshaft position sensor circuit. This sensor (often “A” Bank 1 Sensor 2) keeps track of the camshaft’s position, enabling the ECM to precisely time fuel injection and ignition.
- A failing sensor, disrupted wiring, or poor electrical connection can cause erratic or missing signals—triggering this code. Symptoms might include misfires, rough idle, power loss, or even stalling.
Manufacturer-Specific Meanings
Different carmakers interpret P1340 slightly differently depending on their engine setups:
- Toyota/Lexus: Camshaft Position Sensor ‘A’ Bank 1 Sensor 2 circuit malfunction—meaning the ECM isn’t getting reliable camshaft timing data.
- Jaguar: Similar circuit malfunction, but specifically for Sensor 2 on Bank 2, which typically monitors the exhaust camshaft.
- VW/Audi (and others like Acura/Volvo): The camshaft and crankshaft position sensor signals are “out of sequence”—the ECM expects them to sync up, and when they don’t, it throws this code.
- BMW: Interestingly, BMW associates P1340 with multiple misfires during start, a broader definition implying combustion timing issues.
This variation underlines an important point: whilst P1340 generally points to camshaft/cylinder timing or sensor problems, the exact diagnostics depend on your engine’s design.
Why It’s Important
- Timing is critical – Your engine relies on perfectly timed data from camshaft and crankshaft sensors. When that’s disrupted, performance suffers.
- It’s more than just a check engine light – If ignored, this code can lead to misfires, engine damage, reduced fuel economy, and poor drivability.
Summary Table
| Issue | Description |
| What it means | Detection of faulty camshaft sensor signal or timing sync issue |
| What triggers it | Sensor failure, wiring faults, timing misalignment |
| Effects | Misfires, stalling, rough idle, reduced efficiency |
| Examples by make | Toyota: Camshaft Bank 1 sensor circuitVW/Audi: CKP/CMP out of syncBMW: Multiple cylinder misfires |
“P1340” isn’t just a random set of letters—it’s your car’s way of saying, “Hey, something’s off with camshaft timing or signals!” Whether it’s a bad sensor, wiring hiccup, or timing belt misalignment, this code signals a problem that’s messing with how your engine breathes and runs. And because manufacturers define it differently, always cross-reference your vehicle’s service manual or run a specific diagnostic tailored to your model to decode the full story behind that troubling light on your dash.
How Manufacturers Define P1340 Differently
Understanding what OBD P1340 actually means depends a lot on the make and model of your vehicle. This code isn’t one-size-fits-all—it can signal different issues depending on the manufacturer. Let’s break it down:
Generic / Engine‑Codes Baseline
In a general sense, P1340 points to a problem with the Camshaft Position Sensor ‘A’ on Bank 1, Sensor 2. This sensor helps the engine control module (ECM) precisely time fuel delivery and ignition events.
Audi / Volkswagen (VW)
For Audi and VW, P1340 is logged as “CKP/CMP sensor signals out of sequence.” Simply put, it means the engine’s camshaft (CMP) and crankshaft (CKP) signals aren’t lining up as they should—this mismatch could be from sensor issues or actual timing misalignment.
In fact, enthusiasts on VW forums often reference this:
“The most common reason is cam timing is off… my timing belt was off half a tooth”.
So for VAG‑group vehicles, P1340 tends to be more of a timing alignment flag.
Toyota / Lexus
On Toyota and Lexus engines, especially V6 and inline engines, P1340 relates specifically to “No camshaft position sensor signal from Bank 1 Intake Sensor 2 during cranking or early RPM.”
In plain terms: the ECM isn’t getting the expected signal from that sensor when it starts up. Could be a faulty sensor, wiring issue, or poor connection.
Ford
Ford’s version of P1340 is simply “Camshaft Position Sensor B Circuit Malfunction.” This straightforward description signals an electrical problem—whether it’s the sensor itself, wiring, or connector.
BMW / MINI
BMW and MINI interpret P1340 in a completely different way. Instead of a camshaft sensor issue, they define it as “Multiple Cylinder Misfire During Start.” Early cranking misfires without full RPM sync will trigger this code.
So on these cars, you’re dealing more with ignition/fuel-related misfires—not necessarily cam timing.
Other Manufacturers
- Jaguar: Similar to Toyota/Lexus—they define it as “Camshaft sensor circuit malfunction” on a specific bank and camshaft.
- Peugeot / Mercedes / Mazda: These manufacturers also pick up related camshaft sensor issues or sequence faults, but the exact definition depends on the engine layout .
Why It Varies
- Sensor placement and complexity: English vs. other engines with tooth rings, dual cams, or variable valve timing all impact interpretation.
- Diagnostic strategy: Some brands flag timing this way; others flag related misfires or electrical faults.
- Software logic in the ECM: Manufacturers write different triggers—VW focuses on signal sync, BMW on misfires, Toyota on missing cam input.
So What Should You Do?
If you get a P1340 code, here’s how to troubleshoot based on your brand:
- VW/Audi → check timing chain/belt alignment and both crank and cam sensors.
- Toyota/Lexus/Ford/Jaguar → verify cam sensor wiring, connectors, and the sensor signal itself.
- BMW/MINI → inspect spark plugs, coils, injectors, starter battery health, and misfire counts during cranking.
Quick Comparison Table
| Manufacturer | Interpretation | Probable Focus Area |
| VW/Audi | CKP/CMP signals out of sync | Timing alignment, sensor synchronization |
| Toyota/Lexus | No camshaft signal from Bank 1 Int. | Cam sensor circuit or sensor issue |
| Ford | Camshaft Sensor “B” circuit fault | Sensor wiring or sensor replacement |
| BMW/MINI | Multiple-cylinder misfires at start | Ignition/fuel system faults |
| Jaguar | Camshaft sensor circuit malfunction | Sensor circuit repair |
In a nutshell, OBD P1340 is a shape-shifter—it might be about camshaft sensors, timing alignment, or misfires, depending on your car. That’s why your next move should always be brand-aware: look up your vehicle’s definition of P1340 before jumping into diagnostics. It’ll save you time, money—and a lot of unnecessary parts changes.
Common P1340 Symptoms to Watch For
When OBD P1340 pops up in your scan tool, it’s your car’s way of signaling that something’s off with camshaft timing or sensor alignment. Here’s what you might notice:
1. Check Engine Light Illuminated
This is the first—and often most obvious—sign. The engine control module (ECM) has detected a mismatch in camshaft and crankshaft signals, so the Check Engine Light (CEL) turns on to alert you.
2. Rough or Unstable Idle
You might feel the engine shaking or stuttering when stopped. That rough idling is due to inconsistent timing or misfiring cylinders, common in P1340 situations across brands like BMW, VW, Ford, and Toyota .
3. Loss of Power & Hesitation
Expect sluggish acceleration or a failure to deliver power smoothly, especially at low RPMs. Symptoms include hesitation—and sometimes even engine stumbling. VW/Audi owners often report this along with rough idle and stalling .
4. Engine Misfires
A misfire might feel like a sudden jerk or hesitation while driving or during engine start. BMW—among others—commonly detects multiple cylinder misfires tied to P1340.
5. Engine Stalling or Failed Starts
From hesitation to complete shutdown: P1340 can cause stalling at idle or even prevent the engine from starting when cam/crank signals are too far out of sync .
6. Poor Fuel Economy
A badly timed engine burns fuel less efficiently. Misfires and timing issues translate to wasted gas—so you’ll likely see more trips to the pump .
7. Electrical & Battery-Related Symptoms
In some cases—especially Ford and Toyota—a weak battery or poor starter performance can disrupt sensor signals. You might notice delayed engine cranking or erratic sensor readings. All these quirks can trigger P1340.
Variations by Manufacturer
Different automakers interpret OBD P1340 in unique ways, and diagnostics can vary accordingly:
- BMW: Typically flagged during a multiple-cylinder misfire at startup. You’ll often get supplemental misfire codes.
- VW/Audi: Highlights “CKP/CMP signals out of sequence” and includes low-RPM lag and stalling.
- Ford & Toyota: Expect camshaft sensor circuit malfunctions—paired with rough idle, power loss, or hesitation.
What This Feels Like on the Road
Let’s break it down like a conversation:
“You pop the key…
The engine fires up but it feels shaky, maybe stumbles a bit—like it’s having trouble warming up.
The CEL is staring at you from the dash.
You hit the gas, and—nothing. Feels like you’re pushing through molasses.
And worst? It might even die while you’re stopped or refuse to start at all.”
If any of this sounds familiar, your vehicle might be experiencing P1340-related symptoms.
Why It Matters
Ignoring these symptoms isn’t just risky—it can lead to:
- Engine damage from sustained misfires
- Catalytic converter issues from unburned fuel
- Drain on fuel efficiency and unnecessary wear on engine components
That’s why early detection is key—and why understanding these symptoms is your first step toward fixing the problem.
Quick Symptom Checklist
Here’s a rapid-fire symptom list to consider if you’re dealing with OBD P1340:
| Symptom | What It Means |
| Check Engine Light on | ECM detected timing or sensor issue |
| Rough or Unstable Idle | Inconsistent timing or misfires |
| Power Loss/Hesitation | Signal mismatch affecting engine performance |
| Misfires | Seen in BMW and other complex cases |
| Stalling or Hard Starting | Severe cam/crank timing errors |
| Poor Fuel Economy | Misfires = wasted fuel |
| Electrical/Starter Issues | In Ford & Toyota, battery/starter affect sensor signals |
With these refined symptom insights, you can better communicate with your mechanic—or know exactly what to look for if you’re diving into a DIY fix.
Top Causes Behind the P1340 Code
When your car throws an OBD P1340 code, it means the engine control module (ECM) has detected a timing signal mismatch—typically involving the camshaft and crankshaft position sensors. Here’s what could be going on:
1. Faulty Camshaft Position Sensor (CMP)
The CMP sensor monitors the camshaft’s rotation and sends that data to the ECM. If it fails entirely or sends erratic signals, the timing window is thrown off—triggering P1340. This is one of the most common culprits across all makes. A worn or contaminated sensor often leads to spike interference or dropped signals.
2. Crankshaft Position Sensor (CKP) Issues
Sometimes, it’s the crankshaft sensor that’s faulty. A bad sensor here can disrupt the alignment of cam and crank signals, resulting in a mismatch fault. Heat, vibration, and wiring wear are typical causes, especially in high-mileage vehicles.
3. Timing Chain/Belt Misalignment or Stretch
If your timing belt or chain slips, or the chain stretches over time, your cam and crank don’t stay in sync. It’s often just one tooth out—something that trips P1340 particularly on VW/Audi or BMW engines. Users report that even a “one-tooth off” misalignment triggers rough running and stalls .
4. Wiring or Connector Problems
Don’t overlook the wiring! Frayed wires, broken pins or corroded connectors in the CMP or CKP circuits can block or scramble signals, triggering a false P1340 flag.
5. Starter or Weak Battery (Notably on BMW/Ford)
On certain brands, like BMW and Ford, a weak battery or failing starter can cause voltage drops during startup, which lets the ECM detect misaligned timing—again triggering P1340.
6. Failed Camshaft Phasers, Tensioners, Guides
In variable valve timing (VVT) setups or older engines, worn phasers, hydraulic tensioners, or guides can cause the timing chain to shift under load, misaligning timing. VW owner forums often report this as a hidden source .
7. ECM or Sensor Configuration Errors
Although less common, some reports show that installing the wrong generation sensor (e.g., 4‑gap vs. 1‑gap CMP on Audi VW 1.8T motors) can confuse the ECM and cause P1340. Also, incorrect timing chain component placement—like swapped guides—can throw off signal windows .
So What’s Usually Wrong?
| Cause | Quick Fix |
| Faulty CMP sensor | Replace sensor |
| Faulty CKP sensor | Replace sensor |
| Timing chain/belt off or stretched | Realign or replace chain/belt |
| Wiring & connectors bad | Repair or replace harness/connectors |
| Weak battery / bad starter | Charge/fix or replace; retest after repair |
| Worn VVT parts | Replace phasers, tensioners, guides |
| Mismatched sensor or chain parts | Use correct parts & re-time per specs |
Bottom Line
The OBD P1340 code often signals a sync problem between your camshaft and crankshaft timing signals. Your best bet? Start with the sensors, then check timing alignment, wiring, and power supply. If you’re not confident with this kind of diagnosis, getting help from a trusted mechanic could save time and keep your engine running smoothly.
How to Diagnose OBD P1340 code Correctly
So, your scan tool just spit out P1340 – what now? Let’s walk through diagnosing this issue as clearly (and casually) as chatting over a wrench.
1. Confirm the Code & Scan for Related DTCs
- Plug in an OBD-II scanner and pull the fault codes. Confirm that P1340 is present and check for any other codes like P0016, P0340, or misfire codes. Multiple codes can provide context or clues.
- Take a peek at live data streams if your scanner supports it; compare camshaft and crankshaft sensor RPM values for synchronization issues.
2. Visual Inspection: Start with the Obvious
Often, the simplest issue is a damaged wire or corroded connector:
- Trace the wiring harness for both the camshaft position sensor and crankshaft position sensor. Look for tears, kinks, burnt spots, or oil contamination.
- Inspect connectors for moisture, bent pins, and corrosion. One bad connector can throw off all signal timing.
3. Test Sensor Signals with a Multimeter
- Camshaft Position Sensor (Bank 1 Sensor 2 or Sensor A): Measure resistance per your vehicle’s repair manual specs. Also test for reference voltage (often 5 V) and grounding.
- Crankshaft Position Sensor: Same idea. Make sure both sensors produce solid, consistent signals, especially while cranking the engine.
- Sensors reading open, shorted, or sending erratic signals? That’s a clear lead to sensor replacement.
4. Check Battery & Starter Circuit (Especially BMW, Toyota, etc.)
- A weak battery or faulty starter can cause low or fluctuating sensor voltages, triggering P1340.
- Ensure your battery is fully charged, connections are tight, and the starter draws appropriate current.
- Many guides recommend this as an early diagnostic step.
5. Verify Cam & Crankshaft Timing Alignment
Sometimes it’s deeper than a bad wire or sensor:
- If you hear the dreaded symptoms (rough idle, misfires) and there’s secure wiring with proper sensor output, then timing misalignment may be the culprit.
- On engines with timing belts or chains, inspect the timing marks by removing the timing cover.
- On VW/Audi engines you’ll see “signals out of sequence” diagnostics – often indicating the timing belt was installed incorrectly or has stretched.
6. Cross-Check Manufacturer-Specific Notes
- For VW/Audi, P1340 is often described as “Crankshaft/Camshaft signals out of sequence.” A brief test drive after basic sensor checks may confirm if timing is off.
- In BMW, P1340 might indicate a misfire at start-up (e.g., on cylinder 4), pointing you to check ignition components, vacuum system integrity, and sensor output.
- On Toyota/Lexus, this code is often related to the VVTi system, so diagnostics include verifying sensor data and inspecting variable valve timing components.
7. Clear the Code & Retest
After taking corrective action—like replacing a faulty sensor, repairing wiring, or realigning timing—clear the code, restart the engine, and take a short test drive.
- If P1340 returns, especially under load or at startup, you’ve likely got an underlying mechanical timing issue.
- If it stays clear, take a ride that mimics regular driving conditions and scan again to ensure it’s fixed.
Quick Diagnosis Checklist
| Step | Action |
| 1 | Confirm P1340 and note any additional DTCs. |
| 2 | Inspect wiring/connectors for both cam and crank sensors. |
| 3 | Test sensors’ resistance, voltage, and signal behavior. |
| 4 | Ensure battery & starter voltages are stable. |
| 5 | Check timing belt/chain alignment and timing marks. |
| 6 | Apply any vehicle-specific diagnostic info (VW, BMW, Toyota…). |
| 7 | Clear codes, retest, and monitor for return of P1340. |
Diagnosing OBD P1340 isn’t guesswork—it’s a step-by-step detective process:
- Confirm the code and what sensors it involves.
- Inspect everything in the sensor circuit.
- Test sensors electrically and verify voltage stability.
- Ensure engine timing is physically aligned.
- Tailor your approach based on the specific make/model if needed.
Taking this structured path will save you time, money, and unnecessary parts swaps. Most importantly, you’ll fix the real root cause—whether it’s a wiring glitch, dying sensor, or deeper timing issue—without guesswork.
Effective Repair Strategies for OBD P1340 Code
When that dreaded P1340 code pops up, your engine is telling you something’s off with camshaft-to-crankshaft timing or related sensor circuits. Let’s walk through the most effective repairs, whether you’re diving in yourself or guiding your mechanic.
1. Inspect & Replace the Camshaft Position Sensor
This is often the simplest and most common solution:
- Locate the sensor (commonly near the camshaft or timing belt cover).
- Visually inspect it and the connector for corrosion, broken pins, or buildup.
- Test continuity & voltage with a multimeter—if it’s outside spec or intermittently acting up, it’s toast.
- Swap it out and clear the error code. Voila! You’ve addressed the most likely cause of P1340.
Budget around $100–$300 (parts and labor depending on make/model).
2. Check & Fix Camshaft Sensor Wiring or Connector Issues
Sometimes the sensor itself is fine—the wiring or connector isn’t:
- Look for damaged insulation, cuts, or rodent chew marks.
- Clean out any debris or corrosion and straighten bent pins.
- Perform a voltage drop test: ensure reliable power and ground at the sensor plug.
- If wires are frayed or broken, repair or splice them cleanly and check continuity again.
This often solves the problem without replacing the sensor itself.
3. Verify Timing Chain or Belt Alignment
If wiring and sensor are solid, it’s time to dig deeper:
- P1340 can mean the cam and crank outputs are not synchronized.
- Check timing marks on cam and crank sprockets. These must match factory specs.
- Replace worn timing components—tensioners, chains, belts, guides—as needed.
- Proper engine timing restoration often clears P1340 across multiple brands.
This repair is more involved—expect several hours, parts range from $500–$1,500 depending on complexity.
4. Rule Out Starter or Battery Problems
In specific cases (e.g., BMW, Toyota, Hyundai), P1340 is caused by unreliable voltage during cranking:
- A weak battery or failing starter can corrupt cam/crank sensor readings.
- Test battery load and starter current draw—if either is under par, replace as needed.
- Clean all battery terminals and grounds, ensuring solid electrical contact.
A healthy electrical system ensures accurate sensor signals.
5. Relearn or Reset the Camshaft Position Sensor
Sometimes the electronic control module just needs a clean slate:
- Disconnect negative battery terminal for 10–15 minutes to clear memory.
- Use a scan tool with a “camshaft relearn” or “crank angle relearn” function (if available).
- Start the car and let it idle per the scan tool’s recommendation to re-sync timing logic.
While not a fix for a failing sensor, it can remedy calibration glitches post repair.
6. Test & Replace the Crankshaft Position Sensor (CKP), If Needed
Though less likely, sometimes it’s the crank sensor causing misalignment:
- Just like the cam sensor, check wiring, signal integrity, and physical condition.
- If signal is erratic or absent, replace the crankshaft position sensor.
- Since P1340 arises when the ECM detects cam vs crank mismatch, fixing either one may resolve the code.
7. Clear Codes & Validate the Repair
After your repair steps:
- Clear the P1340 code using your OBD tool.
- Start the engine and monitor live cam/crank signal data.
- Drive for several miles to ensure the code doesn’t return.
- If P1340 comes back, it’s time to re-examine scope areas—timing, sensor, wiring, or PCM.
Quick Fix Summary
| Problem Area | Action Items | Estimated Cost |
| Camshaft Position Sensor | Inspect, test, clean, replace if bad. | $100–$300 |
| Sensor Wiring/Connector | Repair broken wires, clean connectors, test power/ground continuity. | $50–$200 |
| Timing Chain/Belt Misalignment | Check, align, replace worn components. | $500–$1,500 |
| Battery & Starter Voltage Issues | Test & replace weak battery or failing starter. | $100–$400 |
| Camshaft Sensor Relearn/Reset | Disconnect battery or use scan tool relearn features. | Minimal labor/cost |
| Crankshaft Sensor (If Suspect) | Inspect, test, replace if signal faulty. | $150–$300 |
DIY or Call a Pro?
- Easy wins: Replacing sensors or repairing damaged wiring is often DIY-friendly.
- Major timing jobs: Save yourself from engine damage—leave timing belt/chain and phaser work to pros.
- Electrical mystery issues: If you’ve replaced sensors and your timing is correct but the code sticks, it’s time for an expert scan with OEM-level tools.
Taking on the OBD P1340 code might seem technical, but with a methodical approach—start simple (sensor, wiring) and gradually work deeper (timing, electrical system)—you can effectively fix it. If the code reappears, retrace each step, and don’t hesitate to involve a trusted mechanic for advanced diagnostics.
Estimated Cost & Time to Fix P1340
Understanding the cost involved can help you plan better. Here’s what you might expect:
| Repair | Estimated Cost (Parts + Labor) |
| Camshaft Sensor Replacement | $100 – $250 |
| Crankshaft Sensor Replacement | $120 – $300 |
| Timing Chain/Belt Realignment | $500 – $1,200 |
| Wiring Repair | $50 – $200 |
| ECM Update or Reflash | $100 – $250 |
Time Required: Most sensor replacements take under an hour. Timing-related repairs could take several hours depending on engine complexity.
When to Seek Professional Help
While many DIYers can handle sensor replacements, timing corrections and deep electrical diagnostics may require professional tools and expertise. You should see a certified mechanic if:
- The check engine light returns after repairs.
- You notice a persistent rough idle or misfires.
- Timing inspection shows misalignment.
- You’re unsure how to interpret live sensor data.
A trained technician with access to manufacturer-specific diagnostic tools will resolve the issue more accurately.
Preventing Future P1340 Codes
Preventive maintenance can go a long way in keeping this error from returning:
- Regularly inspect and replace timing belts or chains based on manufacturer guidelines.
- Use quality engine oil and change it on schedule to prevent sludge build-up.
- Inspect sensor wiring during routine maintenance.
- Test your battery and starter system regularly, especially in colder climates.
- Don’t ignore early warning signs like misfires or hard starting.
Staying ahead of potential issues helps you avoid unexpected breakdowns and costly repairs.
FAQs: OBD P1340 Troubleshooting Tips
Q1: Can I still drive with a P1340 code?
You may be able to drive short distances, but it’s not advisable. Ignoring the code can lead to engine misfires, poor performance, and long-term engine damage.
Q2: Can I fix the P1340 code myself?
Yes—if the issue is sensor-related and you’re comfortable with basic diagnostics. However, timing or electrical issues are better left to a professional.
Q3: Will resetting the code solve the problem?
No. Resetting the code without addressing the root cause will only clear the check engine light temporarily. The issue will return.
Q4: How do I prevent sensor failure?
Use high-quality engine oil and filters, keep your engine clean, and avoid extreme driving conditions.
Q5: How urgent is a P1340 code?
It’s important to address it as soon as possible to avoid engine timing issues that could escalate into major damage.
Final Thoughts
The OBD P1340 code might seem intimidating, but with the right knowledge and tools, it becomes much more manageable. Whether it’s a simple sensor issue or a deeper timing problem, identifying and resolving it early will save you time, stress, and money. Keep your vehicle well-maintained, pay attention to performance symptoms, and don’t hesitate to seek professional help if needed.
By understanding the root causes and solutions of the P1340 code, you empower yourself to maintain your vehicle more effectively—and stay ahead of costly repairs.
