P1578 GMC Code - Brake Booster Vacuum Sensor Circuit Low Vacuum
Quick Answer
During engine speed at 500 rpm or more for 20 seconds, brakes not applied, BARO input at 72 kPa or more, MAP input at 60 kPa or less, the Powertrain Control Module (PCM) detects the Brake Booster Vacuum (BBV) input of 5 kPa or less for 16 seconds. Common causes include Faulty Brake Booster Vacuum (BBV) sensor, Brake Booster Vacuum (BBV) sensor harness is open or shorted, Brake Booster Vacuum (BBV) sensor circuit poor electrical connection. 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
- P1578 GMC indicates Brake Booster Vacuum Sensor Circuit Low Vacuum.
- Common causes
- Common causes include Faulty Brake Booster Vacuum (BBV) sensor, Brake Booster Vacuum (BBV) sensor harness is open or shorted, Brake Booster Vacuum (BBV) sensor circuit poor electrical connection.
- 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.
Code P1578 GMC Description
What are the Possible Causes of the DTC P1578 GMC?
- Faulty Brake Booster Vacuum (BBV) sensor
- Brake Booster Vacuum (BBV) sensor harness is open or shorted
- Brake Booster Vacuum (BBV) sensor circuit poor electrical connection
How to Fix the DTC P1578 GMC?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1578 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P1578 GMC Code
Q: What does the OBDII code P1578 mean on a GMC vehicle?
1. A: The P1578 code indicates an issue with the Brake Booster Vacuum Sensor Circuit detecting low vacuum levels, which can affect brake performance. 2.
Q: What are common symptoms of the P1578 code in a GMC?
A: Symptoms may include reduced braking power, a hard brake pedal, illuminated check engine light, and potentially longer stopping distances. 3.
Q: What causes the P1578 code to appear on a GMC?
A: Common causes include a faulty brake booster vacuum sensor, vacuum leaks, damaged wiring or connectors, or a failing brake booster. 4.
Q: Can I drive my GMC with the P1578 code active?
A: It’s not recommended, as reduced braking performance can compromise safety. Address the issue as soon as possible. 5.
Q: How do I diagnose the P1578 code on my GMC?
A: Diagnosis typically involves checking the brake booster vacuum sensor, inspecting wiring and connectors, testing the vacuum system, and using a scan tool to monitor sensor data. 6.
Q: How is the P1578 code typically fixed on a GMC?
A: Repairs may include replacing the brake booster vacuum sensor, fixing vacuum leaks, repairing damaged wiring, or replacing the brake booster if necessary. 7.
Q: How much does it cost to fix a P1578 code on a GMC?
A: The cost varies depending on the cause, but brake booster vacuum sensor replacement typically ranges from $100 to $300, plus labor. 8.
Q: Can a faulty brake booster cause the P1578 code on a GMC?
A: Yes, a failing brake booster can cause low vacuum levels, triggering the P1578 code. 9.
Q: Will clearing the code with a scan tool fix the P1578 issue?
A: Clearing the code will temporarily turn off the check engine light, but the issue will return if the underlying problem isn’t resolved. 10.
Q: What happens if I ignore the P1578 code on my GMC?
A: Ignoring the code can lead to reduced braking performance, increasing the risk of accidents and further damage to the braking system.
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