P0665 — Intake Manifold Tuning Valve Control Circuit High Bank 2

Q: Does the ECM really need replacement?

Rarely. Less than 10% of P06xx codes need ECM replacement. Most are power supply issues, software glitches, or water intrusion.

Q: Can I use a junkyard ECM?

Must be reprogrammed to your VIN and immobilizer. Remanufactured pre-programmed units are better.

Q: Can a dead battery cause ECM codes?

Absolutely. Voltage below 10V during cranking corrupts ECM memory and triggers internal fault codes.

What Does P0665 Mean?

P0665 is a diagnostic trouble code indicating: Intake Manifold Tuning Valve Control Circuit High Bank 2. This code relates to the computer and output circuits system. It has been reported in NHTSA complaints across 1 different vehicle models.

The Engine Control Module (ECM) or Powertrain Control Module (PCM) is the central computer managing all engine functions. It processes data from dozens of sensors and controls fuel injectors, ignition coils, VVT solenoids, EGR, EVAP purge, and more. P06xx codes indicate problems within the ECM itself or its internal circuits — these can affect multiple systems simultaneously. Common causes include voltage supply problems (low battery, bad alternator, corroded grounds), software glitches requiring reflash, water intrusion, or genuine internal ECM failure. Before condemning the ECM, ALWAYS verify power, ground, and reference voltage circuits — 90% of suspected ECM failures are wiring or power supply issues. ECM replacement is expensive ($500-$2000+) and requires VIN-specific programming.

Symptoms of P0665

⚠️ Check engine light (possibly multiple warning lights)
⚠️ Multiple unrelated codes stored simultaneously
⚠️ Intermittent no-start or stalling
⚠️ Erratic engine behavior
⚠️ Loss of specific functions (A/C, fans, etc.)
⚠️ Vehicle may enter limp mode

Common Causes

🔍 Low battery voltage or failing alternator
🔍 Corroded or loose ECM ground connections
🔍 Water intrusion into ECM housing
🔍 ECM software requiring reflash/update
🔍 Internal ECM component failure

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"AFTER SEVERAL TIMES THAT THE ENGINE STOPPED RUNNING AND KIA DEALERSHIP COULDN'T FIND THE PROBLEM, AS I TURNED INTO THE DEALERSHIP THE ENGINE STOPPED RUNNING AND I COASTED INTO THE PARKING LOT. REPAIR ORDER STATED POSSIBLE SOLENOID FAILURE (CODE P0665) AND REPLACED BANK 2 INTAKE MANIFOLD TUNING VALV"
— Kia Sportage owner, 02/23/2010

Source: NHTSA Complaints Database

Most Reported Vehicles for P0665

Based on NHTSA owner complaint data.

#	Vehicle	Reports
1	KIA SPORTAGE

Diagnostic Tips

CHECK BATTERY VOLTAGE FIRST — weak battery causes most P06xx codes
Inspect ALL ECM ground connections with voltage drop test (<0.1V)
Check ECM connector for corrosion, bent pins, water intrusion
Check for manufacturer TSBs — many have known software updates

Common Mistakes to Avoid

❌ Replacing ECM without checking power/ground circuits — $500-$2000 mistake
❌ Using junkyard ECM without reprogramming
❌ Ignoring weak battery as root cause

Frequently Asked Questions

Does the ECM really need replacement?

Rarely. Less than 10% of P06xx codes need ECM replacement. Most are power supply issues, software glitches, or water intrusion.

Can I use a junkyard ECM?