Misfire Monitor AICE Chip Fault
The engine's misfire detection system has a faulty chip (AICE) that monitors cylinder combustion events, similar to a smoke detector with a broken sensor that can't tell if there's a real fire. Without this working properly, the engine can't accurately detect misfires and may run rough or damage the catalytic converter.
The AICE (Adaptive Integrated Combustion Electronics) chip processes ionization signals from spark plugs to detect actual flame presence in each cylinder during combustion. The ECM compares these signals against baseline thresholds to identify misfires before they damage emissions equipment.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Ionization signal amplitude | Consistent peak within 50-200mV range per cylinder | Signal loss, noise, or amplitude below 30mV consistently |
| Chip communication/response time | < 10ms response from AICE to ECM | No response or delayed >50ms; chip malfunction detected |
Code P1317 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1317 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.