Nothing’s more frustrating than turning the key only to have your engine fail to start. And “Check Brake System” warning lights may confuse matters further. But various brake problems can indeed prevent starting.
By understanding the brake system’s role in starting, solving issues methodically, and using proper diagnostic steps, you can get your car running again.
Table of Contents
Why Brakes Can Cause No Start Conditions
Modern vehicles have safety interlocks that disable the starter motor if critical systems aren’t operating properly. Two brake components may trigger a car that won’t start:
- Brake Pedal Position Sensor – This senses the pedal position to enable push-button and keyless starting only when the pedal is fully released. Faulty sensors may prevent engine turnover.
- Brake Fluid Level Sensor – Low brake fluid levels or pressure trigger this sensor, which also disables the starter as a safety precaution.
So “Check Brake System” lights coupled with failure to start often point to one of these sensors malfunctioning or being misadjusted. Checking them provides a starting point for diagnoses.
Step-by-Step Diagnosis Process
Methodically troubleshooting the brake system and related components can identify the specific cause preventing starting:
- Check brake fluid level in reservoir – Top off if low.
- Inspect brake pedal position sensor function, location and connectors.
- Ensure shifter is fully in Park/Neutral to allow starting.
- Test brake light switch operation when pedal is pressed.
- Scan for ABS/brake system trouble codes that may disable the starter.
- Check grounding points for any corrosion issues.
By following these steps, you can isolate the sensor or condition responsible for the no start and restore normal operation.
Testing the Brake Pedal Position Sensor
Suspect sensors can be tested to confirm or eliminate them as the no start causes:
- Check under the dash that the pedal arm moves the sensor linkage appropriately when pressing the pedal down.
- Disconnect the sensor electrical connector and check for corrosion or loose pins.
- Use a multimeter to check the sensor resistance values match specifications in pedal released and pressed positions.
- Monitor sensor voltage signals on a scan tool in the released and pressed positions – values should toggle between ~.5V and ~4.5V.
These tests verify sensor functionality, or point to the need for replacement if out of specification or erratic.
Checking Additional Components
If brake sensors test correctly, examine other systems tied to engine starting:
- Shift Lock Solenoid – Test that this only allows shifting out of Park with brake pedal pressed.
- Park/Neutral Position Switch – Confirm this senses shifter position accurately.
- Ignition Switch – Check for opportunities, damage or faulty connections.
- Immobilizer System – Make sure the anti-theft system is not faulty and blocking starting.
- Battery Condition – Weak batteries may not allow proper starter operation.
Expanding your diagnosis beyond just the brake system may uncover other faults preventing starting.
Interim Fixes to Regain Starting
If you’ve confirmed a faulty brake sensor is causing a no start, a couple interim fixes may help you get the car running temporarily:
- Tie or tape down the problematic sensor in the correct position to mimic proper operation. This bypasses the fault long enough to start the engine and move the vehicle for repair.
- Disconnect the battery for 30 seconds to reset computer systems and clear any erroneous fault codes stalling your starting efforts. This may clear the way for the engine to turnover normally.
Use these methods very cautiously just to get mobile for repairs. The underlying issues still require professional attention for safety.
Additional No Start Troubleshooting Tips
While brake faults commonly prevent starting, don’t overlook other basic issues:
- Battery load test – Weak batteries lack power to turn over engines.
- Loose battery cable connections – Severe corrosion or loose terminals interrupt power flow.
- failed starter motor – Mechanical faults inside the starter prevent cranking.
- Poor ignition system grounding – Weak ground paths hinder spark.
It pays to perform basic charging, starting and ignition circuit testing even when brake faults set off “no start” conditions. Cover all bases.
Preventing Brake-Related No Start Issues
Proactive troubleshooting means avoiding starter failures related to your brakes:
- Change brake fluid per maintenance schedule – keeps level sensors happy
- Lubricate brake pedal pivot and linkage points
- Clear dirt and debris from pedal position sensor mounts
- Fix minor brake light switch issues before they worsen
- Repair fluid leaks immediately to prevent low levels
- Ensure shifter linkage adjustments are correct
Routine brake system care reduces odds of being left stranded due to a no start condition.
When to Call for Professional Help
If you’ve followed all testing procedures and attempted interim fixes without success in restarting your engine, expert diagnosis may be required:
- Sophisticated scan tools can access deeper computer data than DIY tools. Specialized brake system testing capabilities also help pinpoint faults.
- Pattern failures of multiple sensors may indicate an underlying electrical issue that an experienced shop can trace more readily.
- Further disassembly or component replacement requires skills and tools you may not possess.
Getting stranded by a no start leaves you desperate for solutions. Seeking professional troubleshooting provides assurance of thorough repairs.
No start conditions accompanied by brake warning lights don’t necessarily mean an easy fix. But methodical diagnosis of sensors and systems, followed by appropriate repairs, overcomes the problem and gets you back on your way. With a little patience and diligence, brake-related no start gremlins can be defeated.
Don’t assume “Check Brake System” warnings coupled with failure to start indicate simple sensor replacement alone. Methodically check fluid levels, linkage adjustments, brake switch function, computer fault codes and grounding integrity among other factors. Temporarily defeating safety interlocks via sensor overrides or computer resets may temporarily allow starting but don’t provide permanent solutions. Professional-grade diagnostics tools and expertise can efficiently unravel difficult, intermittent issues. While brake problems can certainly cause no start headaches, proper troubleshooting keeps you from getting stranded unnecessarily.