B1370 – Ignition Tach Circuit Short To Ground

The ODBII code B1370 indicates a fault in the ignition tach circuit, specifically a short to ground, which means there is an unintended connection that allows electrical current to flow directly to the ground, potentially disrupting the normal operation of the ignition system.

The severity of ODBII code B1370 Ignition Tach Circuit Short To Ground is moderate.

Common Causes For: B1369 Ignition Tach Circuit Short To Battery

• Damaged wiring or connectors in the ignition tach circuit.
• Short circuit in the ignition tach signal wire.
• Faulty ignition coil or ignition module.
• Defective tachometer or instrument cluster.
• Grounding issues in the electrical system.
• Corroded or loose connections in the circuit.

Common misdiagnosis for B1370 Ignition Tach Circuit Short To Ground

• Faulty ignition coil
• Bad spark plugs
• Defective crankshaft position sensor
• Malfunctioning camshaft position sensor
• Wiring issues or shorts in the harness
• Faulty engine control module (ECM)
• Incorrectly installed aftermarket components
• Battery or charging system problems

Common Troubleshooting Steps

When dealing with OBD-II code B1370, which indicates an “Ignition Tach Circuit Short to Ground,” it’s important to follow a systematic approach to troubleshoot the issue. Here are common troubleshooting steps you can take:

• 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 ignition tach circuit for any signs of damage, fraying, or corrosion.
• Look for any loose connections or broken wires that could cause a short to ground.
• Check for Shorts:
• Use a multimeter to check for continuity in the ignition tach circuit. Disconnect the battery and then check for continuity between the circuit and ground. If there is continuity, there is likely a short to ground.
• Inspect the circuit for any pinched or chafed wires that may be making contact with the vehicle’s chassis.
• Test the Ignition Coil and Sensors:
• If the ignition tach circuit is related to the ignition coil or crankshaft position sensor, test these components for proper operation. A faulty ignition coil or sensor can cause issues in the tach circuit.
• Use a multimeter to check the resistance and voltage output of these components according to the specifications in the service manual.
• Check the PCM (Powertrain Control Module):
• Inspect the PCM for any signs of damage or corrosion. A malfunctioning PCM can also cause issues with the ignition tach circuit.
• If possible, perform a software update or reset the PCM to see if that resolves the issue.
• Scan for Additional Codes:
• Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues.
• Repair or Replace Faulty Components:
• Based on your findings, repair any damaged wiring or connectors. Replace any faulty ignition coils, sensors, or the PCM if necessary.
• Clear the Codes and Test Drive:
• After making repairs, clear the trouble codes using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Seek Professional Help:
• If you are unable to identify or resolve the issue, consider seeking help from a professional mechanic or automotive technician who has experience with electrical systems. By following these steps, you should be able to diagnose and address the issue related to the B1370 code effectively.