5-Pin Ignition System Wire Harness Connector – Type A & B Female OEM | Ion Sensing Coil Pack

This 5-pin female connector is used in ignition system harnesses where a higher pin count is required beyond the standard 2-pin or 4-pin ignition connector. The 5-pin configuration is used in ignition coil packs with integrated ion sensing (ionization misfire detection), coil packs with individual cylinder feedback circuits, or ignition modules with combined coil control and sensor input circuits. Available in Type A and Type B housing configurations, bare or with 15cm pre-wired leads.

Key Specifications

• Pin count: 5-pin
• Gender: Female
• Housing types: Type A / Type B (different housing geometries)
• Available as: Bare connector or 15cm pre-wired leads
• Application: Ion sensing ignition coil pack, multi-function ignition module harness

Why 5 Pins? – Ion Sensing Ignition Explained

Standard ignition coil connectors use 2–4 pins (trigger signal, primary power, ground, and optionally a coil current feedback). The 5-pin configuration adds an ion sensing circuit — a technology used by Saab, Volvo, GM, and some BMW applications to detect misfires and knock without a dedicated knock sensor:

• Pin 1 (IGT): Ignition trigger signal from ECU (fires the coil)
• Pin 2 (B+): Coil primary power supply (12V)
• Pin 3 (GND): Coil primary ground
• Pin 4 (IGF): Ignition confirmation feedback — coil sends a signal to the ECU confirming each spark event
• Pin 5 (ION): Ion sensing signal — after the spark event, a small DC bias voltage is applied across the spark plug gap; combustion ions conduct this current, and the ECU reads the ion current waveform to detect misfire, knock, and combustion quality

Ion Sensing vs. Knock Sensor: What’s the Difference?

Traditional knock detection uses a piezoelectric knock sensor mounted on the engine block to detect vibration. Ion sensing detects knock directly in the combustion chamber via the spark plug gap:

• Knock sensor: Detects engine block vibration — indirect measurement, affected by mechanical noise
• Ion sensing: Detects combustion chamber ionization directly — more accurate, can detect individual cylinder knock and misfire simultaneously
• Ion sensing advantage: Can detect pre-ignition (detonation before the spark) which a knock sensor cannot detect until the pressure wave reaches the block

Vehicles Using 5-Pin Ion Sensing Ignition Connectors

• Saab 9-3 / 9-5 (B207/B235/B284): Saab’s Trionic engine management system pioneered ion sensing ignition; the 5-pin connector is used on all Trionic-equipped engines
• Volvo S40/V50/C30/S60/V70 (B4164S/B5254T): Volvo ME7/ME9 with ion sensing coil packs
• GM Ecotec (Z20NET/Z20LEH): Opel/Vauxhall Astra/Vectra/Zafira with ion sensing ignition
• BMW N52/N53: Selected applications with ionization misfire detection

Fault Codes from 5-Pin Ignition Connector Faults

• P0351: Ignition Coil A Primary/Secondary Circuit Malfunction
• P0352: Ignition Coil B Primary/Secondary Circuit Malfunction
• P0353: Ignition Coil C Primary/Secondary Circuit Malfunction
• P0354: Ignition Coil D Primary/Secondary Circuit Malfunction
• P0300: Random/Multiple Cylinder Misfire Detected
• P0301–P0304: Cylinder-specific misfire (if ion sensing circuit is open, ECU cannot confirm spark events)
• P1340 (Saab/GM): Ion sensing circuit fault — specific to ion sensing ignition systems

Frequently Asked Questions

Q: What is the difference between Type A and Type B housing?
A: Type A and Type B use different housing geometries (locking tab position, cavity arrangement) to prevent mis-mating between different coil pack generations or between coil packs on different cylinder banks. Match the type to your existing connector housing.

Q: My car has a misfire but the spark plugs and coils test fine — could this be the connector?
A: Yes. A corroded Pin 5 (ION) causes the ECU to lose the ion sensing signal, which it interprets as a misfire even when combustion is normal. This generates P0300 or cylinder-specific misfire codes with no actual misfire. Test the ion sensing circuit by measuring continuity on Pin 5 from the connector to the ECU harness.

Q: Can I use a 4-pin connector instead of the 5-pin?
A: No. The 5-pin connector is required for ion sensing coil packs. Using a 4-pin connector will leave the ion sensing circuit (Pin 5) unconnected, disabling the ion sensing function and generating fault codes. The ECU may also enter a reduced-performance mode without ion sensing feedback.