OBD Guide

C1777

Vacuum Pressure Circuit Failure

C1777 is an OBD-II diagnostic trouble code meaning: Vacuum Pressure Circuit Failure. Common causes: vacuum hose rupture, vacuum pump malfunction. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Hard brake pedal
  • Unstable engine operation at idle
  • Check Engine Light Illuminates
  • Reduced braking performance

Causes

  • Vacuum hose rupture
  • Vacuum pump malfunction
  • Pressure sensor circuit open
  • Oxidation of connector contacts
  • Solenoid valve failure

How to Fix

  1. Visual inspection of vacuum lines for cracks
  2. Checking the integrity of the wiring harness
  3. Diagnostics of sensor resistance with a multimeter
  4. Testing the operation of the vacuum pump
  5. Replacing damaged components

Related codes

FAQ

What does the C1777 code mean?

C1777 is an OBD-II diagnostic trouble code that indicates: Vacuum Pressure Circuit Failure

What causes a C1777 error code?

The most common causes of C1777 include: Vacuum hose rupture; Vacuum pump malfunction; Pressure sensor circuit open; Oxidation of connector contacts.

How do I fix a C1777 diagnostic trouble code?

To fix C1777: Visual inspection of vacuum lines for cracks. Checking the integrity of the wiring harness. Diagnostics of sensor resistance with a multimeter. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C1777?

Limited driving only, diagnose soon

How much does it cost to fix C1777?

The estimated repair cost for C1777 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat