P1299

Injector High Side Open - Bank 2/Target idle not reached

Powertrain Fuel and Air Metering Injector circuit 🟡 Moderate — Fix within a week ⚠️ Drive with Care
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What This Actually Means

In plain language — no jargon

The fuel injector on Bank 2 has an open circuit (broken connection), preventing fuel delivery and stopping the engine from reaching idle speed. Think of it like a water pipe that's cracked—no fuel flows, so the engine starves and stalls.

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Symptoms You May Notice

3 known symptoms for this code
Engine won't start or stalls immediately after starting
Severe misfire and rough idle on Bank 2 cylinders
Check Engine Light illuminated
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors injector pulse width and fuel trim corrections while attempting to maintain target idle RPM (typically 600-800 RPM). When Bank 2's injector fails to open, fuel delivery drops, idle falls below threshold, and the ECU detects the open circuit through high voltage resistance on the injector driver.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Injector voltage at coil 12V pulse during firing, <0.5Ω resistance Open circuit (infinite resistance) or >5Ω resistance
Engine idle RPM 600–800 RPM at operating temp <400 RPM or stall condition
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Fuel injector wiring connector
Inspect and reseat the connector on Bank 2 injectors; clean corrosion from pins with electrical contact cleaner.
2
Fuel injector harness
Check for cuts, pinches, or burnt insulation in the wiring between ECU and Bank 2 injectors; repair or splice as needed.
3
Fuel injector
Replace the Bank 2 injector if wiring is intact; remove old injector and install new one in the fuel rail.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code P1299 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.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code P1299

What happens after you fix the fault

Once the fault is repaired, P1299 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.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.