Faulty CYP sensor B (internal failure or damaged windings).; Damaged or corroded electrical connector at the CYP sensor or PCM.; Wiring harness issue such as an open circuit, short to ground, or intermittent connection due to chafing or heat damage.; Metal debris or foreign material on the sensor tip interfering with the signal.; Improper sensor air gap or loose mounting.; PCM internal fault (rare but possible).

DTC codes / Honda codes / P1386

P1386 · HondaCYP Sensor B Intermittent Interruption

Q: What does code P1386 mean?

CYP Sensor B Intermittent Interruption. P1386 on Honda vehicles indicates that the powertrain control module (PCM) has detected an intermittent interruption in the signal from the CYP sensor B, which is a cylinder position sensor used to identify cylinder number one for sequential fuel injection and ignition timing. The PCM monitors the CYP signal and sets this code when the signal drops out or becomes erratic for a brief period, often due to a poor electrical connection or a failing sensor.

P1386 on Honda vehicles indicates that the powertrain control module (PCM) has detected an intermittent interruption in the signal from the CYP sensor B, which is a cylinder position sensor used to identify cylinder number one for sequential fuel injection and ignition timing. The PCM monitors the CYP signal and sets this code when the signal drops out or becomes erratic for a brief period, often due to a poor electrical connection or a failing sensor.

SystemPowertrain

Code typeHonda specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms.
Occasional rough idle or misfire, especially when the engine is cold or under load.
Intermittent stalling or hesitation during acceleration.
Difficulty starting or extended cranking time.
Reduced fuel economy or poor engine performance in some cases.

Common causes, most likely first

Faulty CYP sensor B (internal failure or damaged windings).
Damaged or corroded electrical connector at the CYP sensor or PCM.
Wiring harness issue such as an open circuit, short to ground, or intermittent connection due to chafing or heat damage.
Metal debris or foreign material on the sensor tip interfering with the signal.
Improper sensor air gap or loose mounting.
PCM internal fault (rare but possible).

How to diagnose and fix it

Inspect the CYP sensor and its connector for physical damage, corrosion, or loose pins; clean or repair as needed.
Check the sensor air gap and mounting condition; adjust or replace if out of specification.
Perform a resistance test on the CYP sensor and compare to factory specifications; replace if out of range.
Inspect the wiring harness between the CYP sensor and PCM for continuity, shorts, and intermittent faults; repair damaged wires.
Clear the diagnostic trouble codes (DTCs) and test-drive the vehicle to see if the code returns.
If the code persists, substitute a known-good CYP sensor and retest.
As a last resort, diagnose the PCM for internal faults following Honda service procedures.

CYP Sensor B Intermittent Signal Pitfalls

A common oversight is replacing the CYP sensor without first checking the connector terminals for slight looseness that causes intermittent signal loss only when the engine vibrates.
The CYP sensor B signal can be affected by metallic debris attracted to the sensor tip, which is often missed during visual inspection and can cause erratic readings.
Intermittent interruptions are frequently caused by a chafed wire in the harness near the timing cover or exhaust manifold, where heat and vibration damage the insulation.
This code can be set by a poor ground connection at the engine block or PCM, so verifying ground integrity is a step many technicians skip.
A failing ignition coil or spark plug can create electrical noise that mimics a CYP sensor fault, so always check secondary ignition components before condemning the sensor.

Can I keep driving with P1386?

The vehicle may be safe to drive short distances if the only symptom is the check engine light, but avoid aggressive acceleration or heavy loads because an intermittent CYP signal can cause misfires or stalling. Have the fault diagnosed promptly to prevent potential catalytic converter damage from unburned fuel.

Tools that help

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Guidance is general and written for Honda vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.