P1660 - OCC Signal High
The P1660 code indicates that the Engine Control Module (ECM) has detected a voltage signal from the Oil Control Circuit (OCC) that is higher than the expected range. This typically points to a short to voltage in the wiring or a faulty oil control solenoid. The OCC is part of the variable valve timing system, and an incorrect signal can affect engine timing and performance.
01. Most Common Causes
- Short to voltage in OCC wiring harness
- Faulty oil control solenoid
- Damaged ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light on
- Rough idle or engine misfire
- Reduced fuel economy
- Poor engine performance
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect OCC wiring for damage or shorts.
Step 3: Test OCC solenoid resistance and compare to specs.
Step 4: Check voltage at OCC connector with key on; should be within range.
Step 5: If wiring and solenoid are OK, test ECM output or replace ECM.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause engine performance issues and potential damage to the variable valve timing system.
How much does it cost to fix?▼
Repair costs typically range from $100 to $300, depending on whether the issue is a wiring repair or solenoid replacement.