P242AExhaust Gas Temperature Sensor Circuit (Bank 1 Sensor 3)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P242A is the general circuit code for the third exhaust temperature probe on bank 1. Where that probe sits is up to each manufacturer: VW counts it behind the oxidation catalyst on the 2014 Touareg TDI, Deutz places it downstream of the SCR catalyst on its EMR L1 controller. VW sets P242A once the signal voltage climbs above 2.61 V, which fits an open circuit. Deutz splits the code by failure type, -13 for an open, -F0 for a ground fault and -1C for a supply out of range. Ford's 2023 diesels give the number a different job: a probe that strays more than 80 °C from its modelled value for 20 s within one trip. Dedicated low and high faults go to P242C and P242D. Without a trustworthy reading the ECM usually suspends regeneration or DEF dosing.
- What you may notice
- MIL on
- Particulate filter regeneration or DEF dosing suspended
- Implausible or missing value for sensor 3 in the scan tool
- Likely causes
- LikelyOpen circuit or corroded terminal in the sensor connector or harness near the exhaust
- PossibleExhaust temperature sensor 3 failed internally
- PossibleGround fault or sensor supply out of range (failure types -F0/-1C on Deutz)
- RareOn Ford diesels, sensor reading deviating from the exhaust temperature model
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.