Vacuum Reservoir Pressure Sensor Circuit Low
The P2526 code means the vehicle's onboard diagnostic system has detected: Vacuum Reservoir Pressure Sensor Circuit Low. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $500 (parts and labor)
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Common Symptoms
- Hard brake pedal
- Loss of power brake assist
- HVAC mode door stuck
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Large vacuum leak depleting reservoir Very High
- Sensor shorted to ground internally High
- Failed vacuum pump not maintaining pressure Moderate
- Sensor signal wire shorted to ground Low
Step-by-Step Diagnostic Procedure
-
Check vacuum level at reservoir with gauge
-
Listen for vacuum leaks with engine running
-
Test vacuum pump operation and output
-
Measure sensor signal voltage and compare to actual vacuum
Frequently Asked Questions
Is it safe to drive with no power brake assist?
The brakes still function but require significantly more pedal force. Drive only short distances and at low speeds until repaired.
What causes vacuum leaks?
Cracked or disconnected vacuum hoses, a leaking brake booster diaphragm, or a damaged vacuum reservoir are the most common causes.
Can a vacuum pump failure cause P2526?
Yes. On diesel vehicles or turbocharged vehicles that use a vacuum pump, pump failure means no vacuum is generated, causing a low reading.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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