P1362

Code

VOLKSWAGEN P — Powertrain

Cylinder 3 Ignition Circuit Short To B+

Brand: VOLKSWAGEN

Type: P — Powertrain

Views: UK: 29 EN: 50 RU: 40

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Page language: EN

Causes

Short to battery positive (B+) in cylinder 3 coil wiring
Failed/shorted ignition coil (cylinder 3)
Damaged or corroded coil connector or pins
Chafed wiring contacting a fused B+ source or accessory
Faulty engine control module (ignition driver)
Aftermarket wiring or recent repairs causing incorrect routing/connection

Symptoms

MIL/Check Engine lamp illuminated
Rough idle and/or misfire, particularly cylinder 3
Reduced engine power, hesitation or stutter under load
Poor fuel economy
Stored misfire counts or misfire-related drivability faults

What to check

Retrieve freeze-frame and live data with a scan tool; note misfire counts for cylinder 3.
Visual inspection of coil pack, connector, and wiring for damage, corrosion, oil or water.
Disconnect coil 3 harness and measure voltage at harness terminal with ignition ON (check for unexpected B+).
Swap coil 3 with another cylinder’s coil to see if the code follows the coil.
Measure coil primary resistance and compare to spec; inspect secondary if accessible.
Backprobe coil driver with oscilloscope or DVOM to observe switching behavior (look for constant B+ when driver should ground).

Signal parameters

Battery voltage (B+): ~11–14.5 V with ignition ON/engine running.
Expected coil primary resistance (typical range): ~0.4–2 Ω (varies by coil type and model).
Expected coil secondary resistance (typical): ~5 kΩ–15 kΩ (varies by design).
Driver output (primary side): switches between ~0 V (on/ground) and ~B+ (off); pulse width/duty varies with RPM and engine control strategy.
If shorted to B+: driver or harness pin will show ~B+ when it should pull to ~0 V during firing.

Diagnostic algorithm

Safety first: park vehicle, set parking brake, and disconnect battery if performing connector/wiring repairs. Use service manual procedures.
Read and record codes, freeze-frame, and misfire counts with a scan tool. Clear codes and attempt to reproduce if safe.
Perform a careful visual inspection of coil 3, connector, and harness routing for chafing, melted insulation, fluid ingress, or aftermarket taps.
With ignition ON (engine OFF), backprobe the coil 3 harness connector: measure supply and driver pin voltages. Note if constant B+ is present on the driver pin (indicating a short to B+).
Disconnect the coil pack. With coil disconnected, re-measure voltage at the harness: if B+ is still present on the driver pin when it should be switching to ground, suspect wiring short or ECM driver fault.
Swap coil 3 with another cylinder’s coil. If the code follows the coil, replace the coil. If it remains on cylinder 3, continue wiring/ECM diagnosis.
Measure coil primary resistance and secondary (if applicable) per factory spec. Excessively low resistance indicates internal short.
Check continuity from coil connector pins to the ECM connector pins; check for short to battery positive (continuity to B+) and short to ground. Repair any damaged wiring or connectors.
Use an oscilloscope to observe the coil driver waveform while cranking/running; look for proper switching to ground during dwell and absence of stuck-high/B+ signal.
If wiring and coil are confirmed good and harness repaired, yet driver remains at B+, consider ECM/ignition driver replacement only after verifying all other causes.
After repairs, clear codes, perform functional test and road test to confirm code does not return and misfire is resolved.

Likely causes

Damaged ignition coil or internal short in coil pack
Wiring harness insulation worn/chafed and touching B+ circuit
Corroded/loose connector pin at coil or ECM
Shorted pin in harness (between coil power feed and coil driver)
Less likely: ECM ignition driver failure (confirm after wiring/coil checks)

Fault status

⚠️ Status

ECM detected short to battery voltage on ignition circuit for cylinder 3 (ignition driver saw B+ when it should switch to ground).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

Repair manuals

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P1362 — Cylinder 3 Ignition Circuit Short To B+