What is the code C1203 on a Lexus?
As a Lexus owner, encountering a diagnostic trouble code (DTC) like C1203 can be concerning. This code is related to the communication between the Engine Control Module (ECM) and the Skid Control ECU, which is part of your vehicle's braking system. In this article, we’ll break down what the C1203 code means, its potential causes, and how to address it effectively.
What Does the C1203 Code Mean?
The C1203 code on a Lexus indicates a "ECM Communication Circuit Malfunction." This means that the Skid Control ECU, which manages the Anti-lock Braking System (ABS) and Vehicle Stability Control (VSC), is not receiving proper communication from the ECM. This issue can lead to warning lights on your dashboard, such as the ABS or VSC light, and may affect the performance of your vehicle's stability and braking systems.
Common Causes of the C1203 Code
Several factors can trigger the C1203 code. Below are the most common causes:
- Faulty ECM or Skid Control ECU: A malfunction in either of these components can disrupt communication.
- Wiring Issues: Damaged or corroded wiring and connectors between the ECM and Skid Control ECU can cause signal interruptions.
- Low Battery Voltage: Insufficient power supply to the control modules can lead to communication errors.
- Aftermarket Modifications: Improperly installed aftermarket devices, such as alarms or remote starters, can interfere with the communication circuit.
Understanding these causes is the first step in diagnosing and resolving the issue effectively.
How to Diagnose the C1203 Code
Diagnosing the C1203 code requires a systematic approach. Here’s how a professional mechanic would typically address it:
- Use an OBD-II scanner to confirm the presence of the C1203 code and check for any additional codes.
- Inspect the wiring and connectors between the ECM and Skid Control ECU for damage or corrosion.
- Test the battery voltage to ensure it meets the manufacturer’s specifications.
- Verify the functionality of the ECM and Skid Control ECU using specialized diagnostic tools.
- Check for any aftermarket modifications that may be interfering with the communication circuit.
Each step helps narrow down the root cause of the problem, ensuring an accurate diagnosis.
Steps to Fix the C1203 Code
Once the issue has been diagnosed, the following steps can be taken to resolve the C1203 code:
- Repair or replace damaged wiring and connectors.
- Replace the ECM or Skid Control ECU if they are found to be faulty.
- Recharge or replace the battery if low voltage is detected.
- Remove or properly install any aftermarket devices causing interference.
- Clear the code using an OBD-II scanner and test drive the vehicle to ensure the issue is resolved.
Addressing the root cause of the C1203 code will restore proper communication between the ECM and Skid Control ECU, ensuring your Lexus operates safely and efficiently.
Conclusion
The C1203 code on a Lexus is a communication-related issue that can affect your vehicle's braking and stability systems. By understanding its causes and following a systematic diagnostic and repair process, you can resolve the issue effectively. If you’re unsure about tackling this problem on your own, don’t hesitate to bring your vehicle to a trusted auto repair shop like Kevin’s Autos. Our experienced technicians are here to help you get back on the road safely!
Frequently Asked Questions
What is the code for small EVAP leak Lexus?
P0456: Evaporative Emissions System - Small Leak Detected.
What is an ECM EV communication circuit?
DESCRIPTION. The circuit sends TRAC, A-TRAC and VSC control information from the skid control ECU to the ECM, and engine control information from the ECM to the skid control ECU via the CAN communication system.
What is the code for bad camshaft position sensor?
Error code P0340 indicates a malfunction with the camshaft position sensor A circuit. This type of malfunction can cause serious issues that require immediate repair because the underlying cause of the code could damage your vehicle's engine if you continue to drive it.
How to fix a small evap leak?
Contents hide
- 5.1. Replace the Gas Cap.
- 5.2. Replace the Hoses.
- 5.3. Purge Volume Control Valve Repair.
- 5.4. Check the Charcoal Canister Vent Control Valve.
- 5.5. Run a Smoke Test.
Can you drive with a very small EVAP leak?
Driving with an EVAP leak might not seem immediately dangerous, but it can lead to long-term issues if ignored. The potential damage to your vehicle's catalytic converter, fuel efficiency, and emissions system can be costly.
What are the trouble codes for manifold absolute pressure sensor?
Common MAP sensor fault codes
- P0068: MAP/MAF - Throttle Position Correlation.
- P0069: Manifold Absolute Pressure - Barometric Pressure Correlation.
- P0105: MAP Circuit Malfunction.
- P0106: MAP/Barometric Pressure Circuit Range/Performance Problem.
- P0107: Manifold Absolute Pressure/Barometric Pressure Circuit Low Input.
How to fix C1201 code?
Since the cause of the C1201 code is the ABS inlet valve, repairs will consist of replacing the old valve with a new one. This can be difficult to perform sometimes as the inlet valve is usually integrated into the ABS assembly.
What is the code C1203?
The code C1203 on a 2002 Toyota Sequoia it refers to the issue with the ABS Anti-lock Braking System communication circuit. it is also related to a communication error between the Engine Control Module ECM and the Skid Control ECU Electronic Control Unit.
What is Lexus stability control?
Vehicle Stability Control technology helps prevent skidding and loss of control by automatically applying brake pressure to individual wheels.
What is the problem with the C1201 on a Lexus?
``C1201 trouble code is common on lexus when the brake pads wear out and the the caliper pistons extends to maximum. It will cause the brake fluid to drop and the brake fluid level sensor is activated. Once the bake fluid level sensor is activated for more then 4 seconds, It will set the code C1201 in the system.
