P1289 Code: Meaning, Symptoms, Causes & Fix

Overview

Code P1289 indicates a fault in Cylinder Head Temp Sensor High Input, typically within powertrain controls.

Symptoms

rough operation in certain conditions
check engine light
increased fuel use

Common causes

Sensor output out of expected upper range affecting cylinder head temp sensor high input
Signal biased high from short-to-voltage
Connector pin damage/corrosion or harness stress near related components

How to diagnose P1289

Confirm P1289 and capture freeze-frame data with a professional scan tool.
Inspect wiring, connectors, and grounds related to cylinder head temp sensor high input for obvious defects.
Compare live data against expected upper threshold and verify reference voltage.
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 P1289

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

Can you drive with P1289?

Most vehicles can be driven short-term with P1289, 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 (high) in the cylinder head temp sensor high input circuit/system.
Apply the required relearn/adaptation procedure if specified by service information.
Road-test and verify P1289 remains cleared under the conditions that originally set the code.

Fix options

Perform relearn/adaptation if required.
Verify reference voltage and inspect wiring.
Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$200-$900

Common mistakes when diagnosing P1289

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.

P1289 in common vehicles

P1289 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 P1289?

P1289 is commonly set by high faults affecting cylinder head temp sensor high input.

How much does it cost to fix P1289?

For P1289, repair costs are typically $200-$900 depending on exact root cause, labor rates, and part quality.

Can I clear P1289 without repair?

You can clear P1289 temporarily, but the code usually returns until the underlying fault is corrected.