B1364 — Ignition Start Circuit Open

OBD2 code B1364 flags a problem with the ignition system (ignition start circuit open). Short, gentle driving to a shop is usually possible. Common culprits: worn spark plugs or wrong plug gap, failed ignition coil or coil pack, moisture or oil in the spark plug wells.

body electrical

Is it safe to drive?

Drive with caution Drive with caution and avoid load. Ignition faults cause misfires that quickly overheat and destroy the catalytic converter; if the Check Engine Light flashes, stop and fix it first.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm B1364 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many B0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the ignition system for damage, corrosion, chafing or poor contact.
Subsystem check Do a continuity test end-to-end on the ignition start circuit and wiggle the harness while measuring — intermittent opens show up as fluctuating readings.
Subsystem check Swap the coil to another cylinder and see if the fault code follows it.
Subsystem check Inspect spark plugs for wear, oil or carbon tracks and check plug gaps.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm B1364 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1364 (parts and labor, USD, independent shop rates): Repair coil wiring or connector: $80–$250; Replace an ignition coil: $150–$380; Replace spark plugs: $90–$250. Overall, fixing B1364 usually costs between $80 and $380. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

How do I diagnose B1364 myself?

Start with a scan: confirm B1364, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the ignition start, and verify the suspect component against live data before buying parts.

What are the symptoms of B1364?

Drivers most often notice: misfires under load or at idle, Check Engine Light on, hard starting, especially in damp weather, loss of power and jerking.

Will B1364 clear itself?

Sometimes B1364 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What does OBD2 code B1364 mean?

Is it safe to drive with B1364?

Drive with caution and avoid load. Ignition faults cause misfires that quickly overheat and destroy the catalytic converter; if the Check Engine Light flashes, stop and fix it first.

The ignition start circuit plays a crucial role in getting your engine running and keeping it running smoothly. When this circuit develops an open — meaning the electrical pathway is interrupted somewhere — your vehicle's body control module detects the problem and stores trouble code B1364. This code falls within the body electrical category, which means the issue lies specifically with the start-up signaling circuit rather than general engine management functions.

When the circuit is open, current cannot flow to the ignition components that need power during the starting process. Your vehicle's computer won't flag B1364 after just one bad reading; it requires multiple failed verification cycles under specific operating conditions before illuminating the check engine light. The freeze frame data captured alongside B1364 records engine load, RPM, coolant temperature, and vehicle speed at the exact moment the fault occurred — use this information to recreate those conditions during your diagnosis.

Symptoms of B1364

Engine misfires under load or at idle
Check Engine Light illuminated
Difficult engine starts, particularly in damp or humid conditions
Noticeable loss of power and hesitation during acceleration
Decreased fuel efficiency compared to normal driving

Common Causes

The most frequent culprits for B1364 involve the wiring and connectors that make up the ignition start circuit. A disconnected or corroded connector, a pin that has backed out of its housing, or a wire broken somewhere in the harness will interrupt current flow. Blown fuses that feed the ignition start circuit are another common source of this fault. Beyond wiring issues, the problem can stem from an internally failed ignition start switch or, less commonly, a faulty ignition control circuit within the ECM itself. Secondary ignition components like worn spark plugs, an ignition coil or coil pack that has failed internally, damaged coil wiring, or moisture and oil contamination in the spark plug wells can also trigger this code.

How to Diagnose B1364

Connect an OBD2 scanner to your vehicle and confirm B1364 is stored in the system. Save the freeze frame data — it documents the exact engine operating conditions when the fault was detected.
Look for any related diagnostic trouble codes that may point toward the root cause. Check manufacturer technical service bulletins for your specific make and model — many body electrical codes have known fixes or software updates.
Perform a thorough visual inspection of the ignition wiring harness and all associated connectors. Look for damaged insulation, corrosion buildup, chafed wires, or connectors that are not fully seated.
Use a multimeter to conduct an end-to-end continuity test on the ignition start circuit. Gently wiggle the harness while monitoring readings — intermittent opens will show up as fluctuating measurements.
Test individual ignition components systematically. Swap the ignition coil to a different cylinder and clear the code to see if the fault follows the part. Inspect spark plugs for wear, carbon deposits, oil contamination, and verify the gap is within specifications.
Clear the code, complete a full drive cycle that reproduces the conditions stored in the freeze frame, and verify that B1364 does not return.

Repair Options for B1364

Always address the cheapest and most probable causes before replacing expensive components. Common repair approaches include fixing damaged coil wiring or corroded connectors at a parts and labor cost of $80–$250, replacing a failed ignition coil for $150–$380, or installing new spark plugs for $90–$250 depending on your engine configuration.

How Much Does It Cost to Fix B1364?

The total repair cost for B1364 typically ranges from $80 to $380 when using an independent repair shop. The exact amount depends entirely on which component in the ignition start circuit has failed. A simple wiring repair costs far less than an ignition coil replacement, so proper diagnosis before purchasing parts is essential. The most expensive fix is rarely the first one you should pursue.

Can You Drive with B1364?

B1364 carries a caution severity rating. Misfires caused by ignition circuit faults can send unburned fuel into the exhaust system, quickly overheating and destroying the catalytic converter. If your check engine light is flashing rather than solid, pull over immediately and address the problem before continuing — driving with active misfires risks costly secondary damage.