P1938 Code - Brake Switch/Sensor Signal
Quick Answer
The P1938 diagnostic trouble code (DTC) indicates an issue with the brake switch or sensor signal in the vehicle. Common causes include Faulty brake switch, Damaged wiring or connectors, Malfunctioning brake sensor. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1938 indicates Brake Switch/Sensor Signal.
- Common causes
- Common causes include Faulty brake switch, Damaged wiring or connectors, Malfunctioning brake sensor.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P1938 Description
The P1938 diagnostic trouble code (DTC) indicates an issue with the brake switch or sensor signal in the vehicle. The brake switch is a crucial component that sends a signal to the vehicle's electronic control module (ECM) when the brake pedal is pressed. This signal is used by the ECM to control various systems in the vehicle, such as the transmission, cruise control, and brake lights. When the ECM detects an abnormal signal from the brake switch or sensor, it triggers the P1938 code.
Common Causes of P1938
- Faulty brake switch
- Damaged wiring or connectors
- Malfunctioning brake sensor
- ECM issue
- Corrosion or debris affecting the brake switch/sensor
Symptoms of P1938
- Brake lights not working
- Inability to engage cruise control
- Erratic shifting of the transmission
- Vehicle not starting
- Check Engine Light illuminated
How to Fix P1938
- Begin by diagnosing the specific cause of the P1938 code using a diagnostic scanner.
- Inspect the brake switch and sensor for any visible damage or wear.
- Test the wiring and connectors for continuity and repair or replace as needed.
- Check the ECM for any faults or errors and reprogram or replace if necessary.
- Clear the code from the ECM's memory and test the vehicle to ensure the issue has been resolved.
Cost to Fix P1938
The typical repair costs for addressing a P1938 code can vary depending on the specific cause of the issue. In general, replacing a faulty brake switch or sensor can cost between $50 and $200, while repairing damaged wiring or connectors may range from $100 to $300. If the ECM needs to be reprogrammed or replaced, the cost can be higher, potentially exceeding $500. Labor rates at auto repair shops typically range from $80 to $150 per hour, but can vary based on location and other factors. It's advisable to consult with a professional mechanic to get an accurate estimate for the repair.
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Code P1938 Information for Specific Makes
- P1938 Ford — Brake Switch/Sensor Signal
- P1938 Lincoln — Brake Switch/Sensor Signal
- P1938 Mazda — Brake Switch/Sensor Signal
- P1938 Mercury — Brake Switch/Sensor Signal
Frequently Asked Questions about P1938 Code
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