A P013XX code indicates a problem with the ignition confirmation (IGF) signal sent from the igniter to the Engine Control Module (ECM). This malfunction can cause misfires, rough running, and even prevent the engine from starting. This article will guide you through diagnosing and resolving an Igniter Circuit Malfunction, specifically focusing on issues that trigger P013XX codes.
Understanding the Igniter Circuit
In a Distributorless Ignition System (DIS), each cylinder has its own ignition coil and spark plug. The ECM controls ignition timing and sends an ignition trigger (IGT) signal to the igniter. The igniter then activates the primary coil, generating a high voltage in the secondary coil that fires the spark plug. Crucially, after the coil fires, the igniter sends an IGF signal back to the ECM confirming ignition. A P013XX code signifies a problem with this confirmation signal. Let’s break down the wiring:
- Pin 1 (Battery Positive): Supplies 12V from the “INJ” fuse, shared by all coils.
- Pin 2 (IGF): Transmits the ignition confirmation signal to the ECM, shared by all coils.
- Pin 3 (IGT): Receives the individual coil fire command from the ECM, unique to each coil (IGT1, IGT2, IGT3, IGT4).
- Pin 4 (Ground): Provides a ground path for the coil circuit, shared by all coils.
Diagnosing the Problem
A P013XX code affecting all cylinders often points to a problem in the shared IGF circuit. The following diagnostic steps will help pinpoint the issue:
Preliminary Checks:
- Visual Inspection: Examine wiring harnesses and connectors for damage, loose connections, or corrosion. Pay close attention to the coil connectors, as they are prone to breakage.
- Ground Check (Pin 4): Measure resistance between Pin 4 of any coil connector and a known good ground. A reading above 1 ohm indicates a ground issue.
- Power Check (Pin 1): Measure voltage between Pin 1 and Pin 4 of any coil connector. You should read between 9 and 14 volts. A low voltage reading suggests a problem in the power supply circuit.
Advanced Checks (with Coil and ECM Connectors Disconnected):
- IGF Open Circuit Check (Pin 2): Measure resistance between Pin 2 of each coil connector and the IGF1 pin on the ECM connector. A reading above 1 ohm suggests an open circuit in the IGF wire.
- IGT Open Circuit Check (Pin 3): Measure resistance between Pin 3 of each coil connector and its corresponding IGT pin (IGT1, IGT2, IGT3, IGT4) on the ECM connector. A high resistance indicates an open circuit in the IGT wire for that specific cylinder.
- IGF Short to Ground (Pin 2 & IGF1): Measure resistance between Pin 2 of each coil connector and ground, then repeat for the ECM’s IGF1 pin. An OL (Over Limit) reading is expected. Any other reading points to a short circuit.
- IGT Short to Ground (Pin 3 & IGTX): Measure resistance between Pin 3 of each coil connector and ground, then repeat for each corresponding IGTX pin on the ECM. An OL reading is expected, indicating no short circuit.
Common Causes of Igniter Circuit Malfunctions
- Broken or corroded wiring: Especially in the shared IGF wire.
- Damaged or loose connectors: Particularly at the coil and ECM.
- Faulty igniter: Although less common than wiring issues.
- Faulty ECM: While rare, a malfunctioning ECM can disrupt the IGT and IGF signals.
Conclusion
Diagnosing a P013XX code requires a systematic approach to checking the igniter circuit. By following these steps and carefully testing each component, you can effectively pinpoint the source of the malfunction and restore proper engine function. Remember to consult your vehicle’s specific wiring diagram for accurate pin locations and wire colors. Addressing the underlying issue within the igniter circuit is crucial for resolving P013XX codes and ensuring reliable engine performance.
