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DTC codes / GM codes / P1361

P1361 · GMIC Circuit Low Voltage

P1361 on a GM vehicle indicates that the ignition control (IC) circuit has been detected at a voltage lower than expected by the engine control module (ECM). The ECM monitors this circuit to ensure proper communication with the ignition control module (ICM) or ignition coil, and a low voltage condition signals a fault that can disrupt spark timing and engine operation.

SystemPowertrain
Code typeGM specific
SeverityMedium
Fix difficultyIntermediate
AreaIgnition system and misfire

Symptoms you may notice

  • Engine may crank but not start or may stall intermittently
  • Rough idle or misfire under load
  • Reduced engine power or limp mode
  • Check engine light (malfunction indicator lamp) illuminated
  • Often no symptoms besides the warning light, especially if the fault is intermittent

Common causes, most likely first

  1. Damaged or corroded wiring or connector at the ignition control module or coil
  2. Faulty ignition control module (ICM) internal short to ground
  3. Poor ground connection for the ICM or engine block
  4. Open or shorted IC signal wire between the ECM and ICM
  5. Failed engine control module (ECM) driver circuit
  6. Aftermarket alarm or remote start wiring interfering with the IC circuit

How to diagnose and fix it

  1. Inspect the IC circuit wiring and connectors for chafing, corrosion, or loose pins, especially near the ignition coil and ICM.
  2. Check and clean all ground connections for the ICM and engine block, verifying low resistance to battery negative.
  3. Measure resistance and voltage on the IC signal wire from the ECM to the ICM; compare to factory specifications.
  4. Test the ignition control module with a known-good unit or follow the manufacturer's diagnostic flow chart to rule out internal failure.
  5. Verify the ECM is providing the correct reference voltage and ground to the IC circuit; repair or replace the ECM if defective.
  6. Clear the code and perform a road test to confirm the repair, monitoring live data for the IC circuit voltage.

IC Circuit Low Voltage Diagnostic Traps

  • A common oversight is assuming the ignition control module is always at fault, but a simple chafed wire near the exhaust manifold often causes this code.
  • The IC circuit is sensitive to ground quality; a corroded engine ground strap can set P1361 without any visible damage to the module or wiring.
  • Aftermarket remote starters or alarm systems spliced into the ignition circuit frequently introduce low-voltage faults that mimic a failed module.
  • Intermittent P1361 codes may not illuminate the check engine light immediately; always check for pending codes if drivability issues are present.
  • The ECM may store P1361 even when the IC circuit is functioning normally if battery voltage was low during cranking, so verify battery and charging system health first.

Can I keep driving with P1361?

If the engine runs normally and only the warning light is on, you can drive cautiously to a repair shop, but avoid heavy acceleration or long trips. If the engine stalls, misfires, or fails to start, stop driving and have the vehicle towed to prevent safety risks.

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 GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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