P1749 Code: Meaning, Symptoms, Causes & Fix

Overview

Code P1749 indicates a fault in Pressure Control Solenoid Failed Low, typically within powertrain controls.

Symptoms

rough operation in certain conditions
check engine light
increased fuel use

Common causes

Signal pulled low by short-to-ground affecting pressure control solenoid failed low
Sensor output out of expected lower range
Connector pin damage/corrosion or harness stress near related components

How to diagnose P1749

Confirm P1749 and capture freeze-frame data with a professional scan tool.
Inspect wiring, connectors, and grounds related to pressure control solenoid failed low for obvious defects.
Compare live data against expected lower threshold and verify ground/reference circuits.
Check for related DTCs to identify the root-cause chain before replacing parts.
After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code P1749

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with P1749?

Most vehicles can be driven short-term with P1749, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

Repair obvious wiring/connector faults first to prevent repeat parts replacement.
Address the root fault mode (low) in the pressure control solenoid failed low circuit/system.
Apply the required relearn/adaptation procedure if specified by service information.
Road-test and verify P1749 remains cleared under the conditions that originally set the code.

Fix options

Repair connector resistance issues.
Replace failed sensor if signal remains low.
Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$200-$900

Common mistakes when diagnosing P1749

Replacing parts without verifying voltage, ground, and signal integrity first.
Ignoring related stored/pending codes that indicate upstream faults.
Skipping post-repair verification drive cycle and readiness checks.

P1749 in common vehicles

P1749 appears across makes such as BMW, Mercedes-Benz, Audi, Volvo. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes P1749?

P1749 is commonly set by low faults affecting pressure control solenoid failed low.

How much does it cost to fix P1749?

For P1749, repair costs are typically $200-$900 depending on exact root cause, labor rates, and part quality.

Can I clear P1749 without repair?

You can clear P1749 temporarily, but the code usually returns until the underlying fault is corrected.