B1368 – Ignition Tach Circuit Open

The ODBII code B1368 indicates that there is an open circuit in the ignition tachometer circuit, which means the system is not receiving the expected signal from the tachometer.

The severity of ODBII code B1368 Ignition Tach Circuit Open is moderate.

Common Causes For: B1367 Ignition Tach Circuit Failure

• Faulty ignition coil
• Open or shorted wiring in the tach circuit
• Bad connection or corroded terminals
• Defective engine control module (ECM)
• Malfunctioning tachometer or gauge cluster
• Faulty crankshaft position sensor
• Faulty camshaft position sensor

Common misdiagnosis for B1368 Ignition Tach Circuit Open

• Faulty ignition coil
• Bad spark plugs
• Ignition module failure
• Wiring issues or shorts
• Faulty crankshaft position sensor
• Faulty camshaft position sensor
• Engine control module (ECM) issues
• Fuel delivery problems
• Vacuum leaks
• Timing belt or chain problems

Common Troubleshooting Steps

The OBD-II code B1368 indicates an issue with the ignition tach circuit, specifically that it is open. This can be related to the vehicle’s tachometer or the circuit that communicates engine RPM information. Here are some common troubleshooting steps to diagnose and resolve the issue:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information about the ignition tach circuit and wiring diagrams.
• Visual Inspection:
• Inspect the wiring and connectors associated with the tachometer and ignition system for any signs of damage, corrosion, or loose connections.
• Look for frayed wires, broken connectors, or any signs of wear.
• Check Fuses:
• Inspect the fuses related to the ignition system and the instrument cluster. Replace any blown fuses.
• Test the Tachometer:
• If the vehicle has a separate tachometer gauge, ensure it is functioning correctly. If it is not working, it may need to be replaced.
• Check the Ignition System:
• Inspect the ignition coils, spark plugs, and related components to ensure they are functioning properly. A malfunctioning ignition system can affect the tach signal.
• Scan for Additional Codes:
• Use an OBD-II scanner to check for any other trouble codes that may be present. Other codes can provide additional context for the issue.
• Test the Circuit:
• Use a multimeter to test the continuity of the tach circuit. Check for an open circuit by measuring resistance along the wiring.
• Check for proper voltage and ground at the tachometer connector.
• Inspect the PCM/ECM:
• If all other components check out, the issue may lie with the Powertrain Control Module (PCM) or Engine Control Module (ECM). Ensure that it is functioning correctly and that there are no software issues.
• Consult Technical Service Bulletins (TSBs):
• Look for any TSBs related to the B1368 code for your specific vehicle make and model. Manufacturers may have issued guidance on common issues and fixes.
• Professional Diagnosis:
• If the problem persists after performing these steps, consider seeking help from a professional mechanic or technician who has experience with your vehicle make and model. By following these steps, you should be able to identify and resolve the issue related to the B1368 code.