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P1358

IC Output High/Pulse Detected When Grounded Cyl.8.

  • Chevrolet
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
3
AreaIgnition system or misfire
58
FaultThe specific fault in that area

What it means

On a Chevrolet, P1358 means the engine control module has seen a fault on the ignition control (IC) output for cylinder 8. It detected a high signal, or a pulse, on that circuit when the module was commanding it to be grounded (off). This points to a fault in the ignition control circuit, the module driver or the ignition module or coil that it drives. Exact layout varies by model and engine.

Symptoms

  • Malfunction indicator lamp on
  • Engine misfire or rough running, mainly on cylinder 8
  • Hesitation or poor acceleration
  • Rough idle or hard starting
  • Reduced fuel economy
  • Possible flashing warning lamp under load if misfire is severe

Possible causes

  • Short to voltage or crosstalk in the cylinder 8 ignition control wiringlikely
  • Damaged, corroded or loose connector at the ignition coil, ignition module or control modulelikely
  • Faulty ignition coil or ignition module for cylinder 8likely
  • Wiring chafed against another ignition control wire or a hot circuitpossible
  • Poor ground or power supply to the ignition coil or modulepossible
  • Faulty engine control module output driverrare

How to diagnose

  1. Read all stored and pending codes and note freeze frame data, including engine speed, load and temperature when the code set
  2. Check for other ignition or misfire codes, which can show whether the fault is limited to cylinder 8 or wider
  3. Visually inspect the cylinder 8 coil or module, its connector and the wiring for chafing, heat damage, moisture and corrosion
  4. Check the ignition feed and ground circuits for the cylinder 8 coil or module, including voltage drop under load
  5. Test the ignition control wire from the control module to the coil or module for shorts to voltage and for crosstalk with neighbouring wires
  6. Swap the cylinder 8 coil or module with a known good one and see whether the fault follows it, where the design allows
  7. Scope the ignition control signal at the coil connector and compare it with a working cylinder
  8. Check the spark plug condition and gap for cylinder 8, then confirm the control module output only after wiring and components are cleared, following manufacturer procedure for your model

How to fix

  • Repair or replace damaged ignition control wiring and secure it away from sources of interference
  • Clean or replace the faulty connector or terminals
  • Replace the faulty ignition coil or ignition module for cylinder 8
  • Repair poor power or ground connections to the ignition components
  • Replace worn or fouled spark plugs if they are contributing to the fault
  • Replace or repair the engine control module only if the output fault is confirmed after all else is ruled out

Can I keep driving?

Medium severity

It can usually be driven a short distance to get it repaired, but a persistent misfire can overheat and damage the catalytic converter. If the warning lamp flashes or the engine runs very roughly, stop driving and get it checked.

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

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