01 Car Security Systems: What They Are and How to Install Them • 02 BMW Unveils New Armored i7 and V8 7 Series for High-Profile… • 03 Fuel Pressure Regulator Issues: Symptoms and Repairs • 04 The Ultimate Guide to Inspect a Used Car Before Buying • 05 ECU Remapping: What It Is and How It Can Benefit Your Car • 06 Experts Say Most People Use Air Conditioning Wrong And It's… • 07 V10 vs V8 Engine: Which One is Better? • 08 Does Your Car Hesitate When Accelerating? Here's What The P… • 09 Understanding Clutches: Types, Advantages, and Disadvantage… • 10 Is Korean Automotive Culture the Future of Mass Market Cars •

DTC codes / Volkswagen codes / P1342

P1342 · VolkswagenIgnition Coil Power Output State 1 Short To B+

This code means the engine control module (ECM) has detected a short to battery positive voltage on the power output circuit for ignition coil state 1, which is the control wire for one coil or coil group. The ECM commands the coil to fire by pulling that wire low, but it sees the circuit stuck at or near battery voltage when it should be switching.

SystemPowertrain
Code typeVolkswagen specific
SeverityMedium
Fix difficultyIntermediate
AreaIgnition system and misfire

Symptoms you may notice

  • Often no symptoms besides the warning light, especially if the short is intermittent or affects a coil that still fires under most conditions
  • A noticeable engine misfire or rough idle if the affected coil stops firing
  • Loss of power and poor fuel economy while the misfire is active
  • A flashing check engine light if the misfire is severe enough to damage the catalytic converter
  • Slightly rough running or hesitation under load that comes and goes with temperature or vibration

Common causes, most likely first

  1. Chafed or pinched coil control wire shorting to a nearby battery-positive wire in the engine harness
  2. Internal short to power inside the ignition coil itself, pulling the control circuit high
  3. Corroded or water-intruded connector at the coil or at the ECM, bridging the control pin to a power pin
  4. Faulty ECM driver for that coil output, holding the circuit at battery voltage
  5. Aftermarket alarm, remote starter or accessory wiring tapped into the coil harness and shorting to power
  6. Damaged harness from a previous repair, rodent chewing or engine movement wearing through insulation

How to diagnose and fix it

  1. Clear the code and test-drive to confirm it returns, then check freeze-frame data to see whether the fault was present at idle or under load
  2. Inspect the coil connector and the harness near the coil for chafing, corrosion or signs of a previous repair, and wiggle-test the harness while watching live misfire counters
  3. Disconnect the coil and measure resistance from the control wire to battery positive with the key off; any continuity below a few ohms confirms a short to B+
  4. Isolate the circuit by unplugging the ECM and rechecking for continuity to power, which separates a harness short from an internal ECM fault
  5. Check for aftermarket wiring or accessories tapped into the coil circuit and remove or repair any non-factory connections
  6. Repair the harness section with a proper splice and heat-shrink, or replace the affected coil if the short is internal to it
  7. After repair, clear codes, run a full drive cycle and verify the misfire counters stay at zero and the code does not reset

What a short to B+ really means here

  • A short to B+ does not mean the coil is dead; the ECM is reporting that the control wire is being held at battery voltage, which can come from the harness, a connector or the coil itself.
  • Technicians often replace the coil first and the code returns because the actual short is a chafed wire a few inches back in the loom where it rubs on the engine cover or a bracket.
  • An intermittent short that only appears when the engine is hot or vibrating will not show on a cold static resistance test, so wiggle-testing the harness while monitoring misfire data is essential.
  • Aftermarket remote starters and alarm installers frequently tap the coil power circuit, and a poor splice there can set this code long after the accessory was installed.
  • If the short persists with the coil disconnected and the ECM unplugged, the fault is in the harness; if it disappears with the ECM unplugged, suspect the ECM driver itself.

Can I keep driving with P1342?

You can drive carefully to a repair shop if the engine runs smoothly and the light is steady, but avoid hard acceleration and long trips. If the check engine light is flashing or the engine misfires badly, stop driving because raw fuel can overheat and destroy the catalytic converter.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage