P1284 - ICP Failure Aborts KOER CCT Test
The P1284 code indicates that the Injector Control Pressure (ICP) sensor has failed during the Key On Engine Running (KOER) Continuous Cylinder Contribution Test (CCT). This typically means the ICP sensor is not providing a valid signal, or the high-pressure oil system is unable to maintain proper pressure for injector operation. The PCM aborts the test to prevent engine damage.
01. Most Common Causes
- Faulty ICP sensor
- Wiring or connector issues to ICP sensor
- Low engine oil level or incorrect oil viscosity
- High-pressure oil pump failure
- Internal engine oil leak (e.g., injector O-rings)
02. Symptoms You Will Notice
- Check Engine Light on
- Hard starting or no start
- Rough idle or misfire
- Reduced engine power
- Engine stalls
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and check freeze frame data.
Step 2: Inspect ICP sensor connector for corrosion, damage, or loose pins.
Step 3: Test ICP sensor signal voltage with a multimeter (should be ~0.2-4.8V depending on pressure).
Step 4: Check engine oil level and condition; ensure correct viscosity.
Step 5: Perform a high-pressure oil system leak test (e.g., using a pressure gauge).
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, driving with P1284 can cause stalling, hard starting, and potential engine damage. It is recommended to have the vehicle towed to a repair shop.
How much does it cost to fix?▼
Repair costs vary: ICP sensor replacement is $150-$300; high-pressure oil pump repair can be $800-$1500. Diagnosis is typically $100-$150.