P0787 Code: Meaning, Symptoms, Causes & Fix

Overview

P0787 is triggered when monitoring logic identifies an issue with Shift Timing Solenoid A low affecting engine synchronization and valve timing.

Symptoms

loss of power at mid/high RPM
engine noise or unstable timing
rough running or misfire

Common causes

Sensor output out of expected lower range affecting shift timing solenoid a low
High circuit resistance
Connector pin damage/corrosion or harness stress near related components

How to diagnose P0787

Confirm P0787 and capture freeze-frame data with a professional scan tool.
Inspect wiring, connectors, and grounds related to shift timing solenoid a 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 P0787

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

Can you drive with P0787?

Most vehicles can be driven short-term with P0787, 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 shift timing solenoid a low circuit/system.
Apply the required relearn/adaptation procedure if specified by service information.
Road-test and verify P0787 remains cleared under the conditions that originally set the code.

Fix options

Repair connector resistance issues.
Verify ground path and signal integrity.
Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$300-$1400

Common mistakes when diagnosing P0787

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.

P0787 in common vehicles

P0787 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 P0787?

P0787 is commonly set by low faults affecting shift timing solenoid a low.

How much does it cost to fix P0787?

For P0787, repair costs are typically $300-$1400 depending on exact root cause, labor rates, and part quality.

Can I clear P0787 without repair?

You can clear P0787 temporarily, but the code usually returns until the underlying fault is corrected.