Faulty or drifting exhaust gas temperature sensor 2; Damaged, chafed or heat-affected wiring to the sensor; Corroded, loose or contaminated connector at the sensor or control unit plug; Exhaust leak near the sensor giving false temperature readings; Underlying exhaust or aftertreatment fault, such as a blocked or failing filter or catalyst, causing real temperatures to differ from expected; Sensor fitted in the wrong position, or damaged during earlier exhaust work; Engine control unit fault or outdated software, where a known fix exists for that model.

P1459

Exhaust Gas Temperature Sensor 2 Range Performance.

Volkswagen
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
4: AreaAuxiliary emission controls
59: FaultThe specific fault in that area

What it means

P1459 on a Volkswagen means the engine control unit has judged that Exhaust Gas Temperature Sensor 2 is reading in a way that does not make sense. The signal may be out of its expected range, or it may not match the temperature predicted from engine load, running time or the other exhaust temperature sensor. Which sensor is number 2, and where it sits in the exhaust, depends on the model and engine.

Symptoms

Engine warning light on
Reduced power or limp mode on some engines
Poor or incomplete particulate filter regeneration on diesel models
Higher fuel consumption than usual
Other exhaust temperature or emissions-related fault codes stored alongside

Possible causes

Faulty or drifting exhaust gas temperature sensor 2likely
Damaged, chafed or heat-affected wiring to the sensorlikely
Corroded, loose or contaminated connector at the sensor or control unit plugpossible
Exhaust leak near the sensor giving false temperature readingspossible
Underlying exhaust or aftertreatment fault, such as a blocked or failing filter or catalyst, causing real temperatures to differ from expectedpossible
Sensor fitted in the wrong position, or damaged during earlier exhaust workrare
Engine control unit fault or outdated software, where a known fix exists for that modelrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting temperature, load and engine speed when the fault was set.
Check for related codes covering other exhaust temperature sensors, the particulate filter, catalyst or boost, and deal with those first.
Visually inspect the sensor, its wiring and the connector for heat damage, chafing, oil or water ingress and corrosion.
Inspect the exhaust around the sensor for leaks, damage or signs of recent repairs.
With the engine fully cold, compare live exhaust temperature sensor 2 against sensor 1, coolant and intake air temperature; they should be close to each other.
Watch the live reading as the engine warms and under load, looking for a frozen, jumping or implausibly slow-moving value.
Test the sensor and its wiring for resistance, continuity and shorts against the manufacturer's specification for that engine.
Check for a relevant software update or technical bulletin for the vehicle and engine.

How to fix

Repair or replace damaged wiring and clean or renew a corroded connector.
Replace exhaust gas temperature sensor 2 with a correct part for the engine if it fails testing.
Repair any exhaust leak near the sensor.
Fix any underlying filter, catalyst or engine fault that is causing abnormal exhaust temperatures.
Apply a manufacturer software update only if it is a known fix for this fault on that model.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but get it checked soon. If power is reduced, warning lights flash or the engine is running badly, limit driving, as a faulty temperature reading can affect filter regeneration and protection of exhaust components.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.