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Severity: High Code type: Manufacturer-specific (Volkswagen)

Volkswagen P1340 Code Meaning

The cam signal no longer lines up with the crank signal – often a jumped belt or stretched chain.

At a glance

Severity: 4/5 – High4/5

Severity: High

Meaning
Crankshaft/Camshaft Sensor Signals Out of Sequence
System
Ignition & Misfire · Powertrain
Safe to drive?
With caution
Typical repair cost
$90–$3,500
DIY difficulty
Hard

P1340, shown by VCDS as 17748 'Camshaft Position Sensor (G40) / Engine Speed Sensor (G28): Incorrect Correlation', is set when the camshaft pulse doesn't arrive where the ECU expects it relative to the crankshaft reference gap. On VWs of the Mk4 era – 1.8T, 2.0 8V and the chain-driven VR6 – that is most often a mechanical timing problem: a timing belt that has jumped a tooth or was installed off by one, a stretched chain, or a worn chain tensioner. A failed sensor or a wrong-type cam sensor after a repair can cause the same code, but because the 1.8T and 2.0 are interference engines, you should rule out timing before anything else. Newer VAG engines report the same condition as P0016.

How to read P1340

How to read P1340P11233404
  1. P Powertrain
  2. 1 Manufacturer-specific
  3. 3 Ignition / misfire
  4. 40 Specific fault

Symptoms

  • Check engine light with P1340 (VCDS 17748)
  • Long cranking before the engine starts, or no start
  • Noticeable loss of power and rough running
  • Rattle from the timing end at cold start (VR6 chain, 1.8T cam chain tensioner)
  • Code appeared right after a timing belt or cam chain tensioner replacement

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Timing belt jumped a tooth or was installed one tooth off 30%
  2. Stretched timing or cam chain, worn tensioner or guides (VR6, 1.8T cam chain) 25%
  3. Failed camshaft position sensor G40 15%
  4. Failed crankshaft/engine speed sensor G28 or damaged trigger wheel 10%
  5. Damaged wiring or shielding picking up interference 8%
  6. Wrong G40 version installed (single-window vs four-window trigger on 1.8T) 6%
  7. Low oil pressure affecting the 1.8T chain tensioner/cam adjuster 6%

Diagnosis step by step

Diagnostic flow: P13401Check history before touchingsensors2Verify timing marks3Check chain condition4Test the sensors5Confirm correct parts and oilpressure

  1. Check history before touching sensors

    Read the code and freeze frame and ask about recent work. P1340 appearing right after a belt job almost always means the timing is off; a code that came with a new noise suggests chain or tensioner wear.

    Tools: OBD-II scanner

  2. Verify timing marks

    Remove the upper timing cover, set the crank to TDC on its mark and check that the cam sprocket mark lines up with the mark on the head. On the 1.8T also count the chain rollers between the exhaust and intake cam notches: there should be 16. Anything off by a tooth needs correcting before further tests.

    Tools: Flashlight, Screwdriver

  3. Check chain condition

    On the VR6 listen for rattle on a cold start and inspect the chain slack with the valve cover off. On the 1.8T, look for worn tensioner pads and check the cam adjustment values in VCDS while the engine runs – values drifting toward their limits point to wear.

    Tools: OBD-II scanner, Flashlight

  4. Test the sensors

    Back-probe G40: a Hall sensor needs about 5 V supply and ground and should switch cleanly while cranking. G28 on these engines is usually inductive; measure its resistance against spec and inspect the connector for oil.

    Tools: Multimeter

  5. Confirm correct parts and oil pressure

    If the cam sensor or tensioner was recently replaced, confirm the part matches the engine code – single and four-window versions exist. On a 1.8T with sludge history, check oil pressure; a partly blocked pickup can starve the tensioner.

    Tools: Flashlight

Where the parts are

Ignition: coils and spark plugs per cylinder – P13401234567
Ignition: coils and spark plugs per cylinder
  1. 1Ignition coil
  2. 2Spark plug
  3. 3Fuel injector
  4. 4Camshaft sensor
  5. 5Crankshaft sensor
  6. 6Engine computer (ECM)
  7. 7Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Re-time the engine (belt jumped or installed wrong) No $250–$600
Timing belt kit with water pump No $550–$1,100
1.8T cam chain tensioner gasket/pad set No $250–$550
VR6 timing chain, guides and tensioners No $1,800–$3,500
Replace cam or crank sensor Yes $90–$300

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Audi

Audi's 1.8T in the A4 B5/B6 and TT uses the same belt-plus-cam-chain layout; P1340/17748 after a timing belt job is a classic sign the cam chain or belt was set a tooth off.

Emissions / smog test impact

Will fail

P1340 turns on the check engine light and fails the OBD-II test. More importantly, get timing confirmed before driving to an inspection.

Frequently asked questions

Can a timing belt be off by one tooth and still run?

Yes, and that's exactly when P1340 tends to appear. The engine runs, but with less power and a longer crank, and the ECU notices the cam signal is out of place.

What does 17748 mean in VCDS?

It's the VAG five-digit number for P1340, displayed as '17748 – Camshaft Position Sensor (G40) / Engine Speed Sensor (G28): Incor. Correlation'. Ross-Tech lists it as 17748/P1340/004928.

Should I just replace the cam sensor?

Only after the timing checks out. Sensors do fail, but replacing one when the belt has jumped wastes money and delays the repair that actually protects the engine.

Why does my newer VW show P0016 instead?

Later VAG engines use the generic P0016 for crank/cam correlation. P1340 is mainly seen on Mk4-era cars and some early Mk5 engines.

Sources