The B1355 diagnostic trouble code (DTC) indicates a problem within the ignition run circuit of a vehicle. This circuit is crucial for providing power to various components when the ignition switch is in the "run" position. A failure in this circuit can lead to a variety of issues, from a vehicle not starting to malfunctions in different electrical systems. Understanding the causes, symptoms, and troubleshooting steps associated with B1355 is essential for proper diagnosis and repair.

This code's appearance signifies that the vehicle's computer (typically the Body Control Module or BCM) has detected an unexpected voltage or lack of voltage within the ignition run circuit. This discrepancy disrupts the normal operation of systems powered by this circuit, triggering the DTC.

B1355 Ignition Run Circuit Failure: In-Depth Analysis

| Category | Description | Possible Causes
Symptoms | Associated Problems | Diagnostic Steps !!

Detailed Explanations:

  • Symptoms: These are the noticeable issues that arise due to a B1355 error. They can include anything from systems not functioning to the car not starting.
  • Associated Problems: This refers to the underlying reasons why the B1355 code is triggered. It could be a faulty ignition switch, damaged wiring, or a malfunctioning module.
  • Diagnostic Steps: The process of identifying the root cause of the B1355 code. This involves using diagnostic tools, visual inspections, and electrical testing.

Decoding the B1355 Code

The B1355 code indicates a malfunction in the ignition run circuit. To fully understand the problem, it's crucial to know what this circuit does and how it operates.

The Ignition Run Circuit: This circuit provides power to various vehicle components when the ignition switch is in the "run" position. This power is essential for the operation of systems like the fuel pump, ignition system, sensors, and various control modules. When the BCM detects an issue with the voltage level in this circuit (either too high or too low), it triggers the B1355 code.

Common Symptoms of a B1355 Code

A B1355 code can manifest in a variety of ways, depending on the specific vehicle and the nature of the fault. Here are some of the most common symptoms:

  • Vehicle Not Starting: The most drastic symptom. If the ignition run circuit is completely non-functional, essential components like the fuel pump and ignition system won't receive power, preventing the engine from starting.
  • Intermittent Starting Problems: Sometimes, the issue might be intermittent. The vehicle might start sometimes but fail to start at other times. This can be caused by a loose connection or a failing component that works sporadically.
  • Engine Stalling: If the ignition run circuit fails while the engine is running, it can cause the engine to stall suddenly.
  • Malfunctioning Gauges and Instruments: Many gauges and instruments rely on the ignition run circuit for power. A fault in this circuit can cause these gauges to display incorrect readings or fail to work altogether.
  • Non-Functional Accessories: Accessories like the radio, power windows, and climate control system might not function properly if they are powered by the ignition run circuit.
  • Check Engine Light On: The check engine light (or malfunction indicator lamp - MIL) will illuminate to alert the driver to the problem.
  • Stored Diagnostic Trouble Code (DTC): The B1355 code will be stored in the vehicle's computer memory, which can be retrieved using a scan tool.

Possible Causes of B1355

Several factors can contribute to a B1355 code. A systematic approach to diagnosis is necessary to pinpoint the exact cause.

  • Faulty Ignition Switch: The ignition switch is the primary component controlling the ignition run circuit. A defective switch can fail to provide consistent power to the circuit.
  • Damaged Wiring: Damaged, corroded, or shorted wiring within the ignition run circuit can disrupt the flow of electricity and trigger the code. This includes wires, connectors, and terminals.
  • Faulty Relay: Relays are used to control the flow of power in the ignition run circuit. A malfunctioning relay can cause the circuit to fail.
  • Defective Body Control Module (BCM): While less common, a faulty BCM can misinterpret the voltage in the ignition run circuit and incorrectly trigger the B1355 code.
  • Open Circuit: A break in the wiring, a loose connection, or a blown fuse can create an open circuit, preventing power from reaching the intended components.
  • Short to Ground: If the ignition run circuit wire is shorted to ground, it can cause a voltage drop that triggers the code.
  • Corroded Connectors: Corrosion on electrical connectors can increase resistance and interfere with the flow of electricity.
  • Blown Fuse: A blown fuse in the ignition run circuit is a common cause, often resulting from a short circuit. Always replace a blown fuse with one of the same amperage.
  • Loose Connections: Loose connections in the wiring harness or at the ignition switch can cause intermittent problems and trigger the B1355 code.
  • Aftermarket Accessories: Poorly installed aftermarket accessories can sometimes interfere with the ignition run circuit.

Diagnosing the B1355 Code: A Step-by-Step Guide

Diagnosing a B1355 code requires a logical and methodical approach. Here's a step-by-step guide to help you pinpoint the problem:

  1. Retrieve the DTC: Use an OBD-II scan tool to retrieve the B1355 code and any other related DTCs. Note all the codes present, as they may provide additional clues.
  2. Clear the Codes and Test: Clear the codes and attempt to start the vehicle. If the B1355 code returns immediately, proceed to the next steps. If it doesn't return, the problem may be intermittent.
  3. Inspect the Wiring and Connectors: Carefully inspect the wiring and connectors associated with the ignition run circuit. Look for signs of damage, corrosion, or loose connections. Pay close attention to the wiring near the ignition switch, relays, and BCM.
  4. Check the Fuses: Locate the fuses associated with the ignition run circuit and check them for continuity using a multimeter. Replace any blown fuses.
  5. Test the Ignition Switch: Use a multimeter to test the ignition switch for proper operation. Check for voltage at the appropriate terminals when the switch is in the "run" position. Refer to the vehicle's wiring diagram for the correct testing procedure.
  6. Test the Relay: Locate the relay associated with the ignition run circuit and test it for proper operation. You can use a multimeter to check for continuity and voltage. You can also swap the relay with a known good relay to see if the problem is resolved.
  7. Check for Voltage Drops: Use a multimeter to check for voltage drops in the ignition run circuit. This can help identify areas of high resistance caused by corroded connectors or damaged wiring.
  8. Test the BCM: If all other components appear to be functioning correctly, the BCM may be the cause of the problem. However, BCM testing requires specialized equipment and expertise. It's best to consult with a qualified technician for BCM diagnosis and replacement.
  9. Consult Wiring Diagrams: Obtain a wiring diagram for your vehicle's ignition run circuit. This will help you trace the circuit and identify all the components involved.

Tools Required for Diagnosis:

  • OBD-II Scan Tool
  • Multimeter
  • Wiring Diagram
  • Test Light
  • Basic Hand Tools

Repairing the B1355 Code

The repair strategy for a B1355 code depends on the underlying cause. Here are some common repair procedures:

  • Replace Faulty Ignition Switch: If the ignition switch is defective, replace it with a new one.
  • Repair or Replace Damaged Wiring: Repair or replace any damaged, corroded, or shorted wiring. This may involve splicing wires, replacing connectors, or replacing entire wiring harnesses.
  • Replace Faulty Relay: If the relay is malfunctioning, replace it with a new one.
  • Replace Faulty BCM: If the BCM is defective, it will need to be replaced and reprogrammed. This is a complex procedure that should be performed by a qualified technician.
  • Clean Corroded Connectors: Clean any corroded connectors with electrical contact cleaner.
  • Tighten Loose Connections: Tighten any loose connections in the wiring harness or at the ignition switch.
  • Remove Aftermarket Accessories: If a poorly installed aftermarket accessory is interfering with the ignition run circuit, remove it.

Preventing Future B1355 Issues

While some B1355 codes are unavoidable, there are steps you can take to minimize the risk of future problems:

  • Regular Maintenance: Perform regular vehicle maintenance, including checking and cleaning electrical connections.
  • Proper Installation of Accessories: Ensure that any aftermarket accessories are installed correctly by a qualified technician.
  • Protect Wiring: Protect wiring from damage by using wire looms and secure mounting points.
  • Address Problems Promptly: Address any electrical problems promptly to prevent them from escalating.

Frequently Asked Questions

  • What does the B1355 code mean? The B1355 code indicates a malfunction in the ignition run circuit, meaning the vehicle's computer has detected an incorrect voltage level in the circuit that powers components when the ignition is in the "run" position. This can prevent the engine from starting or cause various electrical system malfunctions.

  • Can I drive my car with a B1355 code? It depends on the severity of the issue. If the vehicle starts and runs normally, you might be able to drive it, but it's best to get it checked as soon as possible to prevent further damage or a complete breakdown. If the vehicle doesn't start or stalls, driving is not recommended.

  • How much does it cost to fix a B1355 code? The cost varies depending on the cause. A simple fix, like replacing a fuse, might cost only a few dollars. However, more complex repairs, like replacing the ignition switch or BCM, can cost several hundred dollars.

  • Is the B1355 code serious? Yes, it can be serious because it affects the ignition run circuit, which is essential for many vehicle functions. Ignoring this code could lead to a complete breakdown or damage to other electrical components.

  • Can a bad battery cause a B1355 code? While not a direct cause, a weak or failing battery can sometimes contribute to electrical issues that might indirectly trigger the B1355 code. A weak battery can cause voltage fluctuations that the BCM interprets as a fault in the ignition run circuit.

Conclusion

The B1355 Ignition Run Circuit Failure code can be a frustrating issue, but with a systematic approach to diagnosis and repair, it can be resolved effectively. Understanding the symptoms, potential causes, and diagnostic steps outlined in this article will help you troubleshoot the problem and get your vehicle back on the road. Always consult a qualified technician if you are unsure about any aspect of the diagnosis or repair process.