P1667 - CID Circuit Failure
The P1667 code indicates a failure in the Cylinder Identification (CID) circuit, which is part of the ignition system. This circuit is responsible for identifying which cylinder is firing to ensure proper ignition timing and fuel delivery. A failure can cause misfires, rough running, and potential engine damage if not addressed.
01. Most Common Causes
- Faulty CID sensor
- Wiring or connector issues in the CID circuit
- Engine control module (ECM) failure
02. Symptoms You Will Notice
- Check Engine Light on
- Engine misfire or rough idle
- Poor acceleration or hesitation
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes.
Step 2: Visually inspect the CID sensor and its wiring for damage or corrosion.
Step 3: Test the CID sensor resistance and signal with a multimeter per manufacturer specs.
Step 4: If sensor and wiring are okay, test the ECM output to the CID circuit.
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 misfires and potential damage to the catalytic converter.
How much does it cost to fix?▼
Typically between $50 and $150 for parts and labor, depending on the cause and vehicle model.