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P1352

IC Output High Pulse Detected When Grounded Cyl 2.

  • GMC
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
3
AreaIgnition system or misfire
52
FaultThe specific fault in that area

What it means

On GMC vehicles, P1352 means the engine control module has seen an ignition control (IC) output pulse on the cylinder 2 circuit at a time when it expected the circuit to be grounded, or the circuit is not behaving as commanded. It is an ignition control circuit fault tied to cylinder 2 and is usually found on older GM systems with a separate ignition module or coil driver. The exact layout depends on the model and engine.

Symptoms

  • Engine misfire, particularly on cylinder 2
  • Rough idle or hesitation under load
  • Malfunction indicator lamp on
  • Poor fuel economy
  • Hard starting or extended cranking
  • Engine stalling in some cases

Possible causes

  • Damaged, chafed or shorted wiring in the cylinder 2 ignition control circuitlikely
  • Corroded or loose connector at the ignition module, coil or engine control modulelikely
  • Faulty ignition coil or coil driver for cylinder 2possible
  • Faulty ignition control module (on systems that use a separate module)possible
  • Poor engine or module earth connectionpossible
  • Fault within the engine control modulerare

How to diagnose

  1. Read all stored and pending codes and note the freeze frame data (engine speed, load, temperature) to see when the fault occurred.
  2. Check for other ignition or misfire codes, which can point to a shared wiring or module fault.
  3. Visually inspect the cylinder 2 ignition wiring and connectors for chafing, heat damage, corrosion, water ingress or bent pins.
  4. Check the engine and module earth connections for cleanliness and tightness.
  5. Inspect the cylinder 2 spark plug and coil for damage, cracks or carbon tracking.
  6. With the engine off, test the control circuit for shorts to earth, shorts to voltage and resistance against the wiring diagram for your model and engine.
  7. Swap the cylinder 2 coil with another cylinder, if the design allows, and see whether the fault or misfire follows it.
  8. Check the ignition module and its supply and earth feeds with a scope or multimeter, following the manufacturer's procedure for your engine.

How to fix

  • Repair or replace damaged wiring and renew faulty connector terminals.
  • Clean and secure engine and module earth connections.
  • Replace the faulty ignition coil for cylinder 2, and fit new spark plugs if worn or fouled.
  • Replace a faulty ignition control module once wiring and supplies are confirmed good.
  • Replace or reprogram the engine control module only after all other causes are ruled out, as specified by the manufacturer.

Can I keep driving?

Medium severity

Short trips are possible if the engine runs reasonably, but a continuing misfire can overheat and damage the catalytic converter, so get it fixed soon. Avoid heavy loads and stop driving if the engine runs badly or the warning lamp flashes.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

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