P242A code meaning
Exhaust Gas Temperature Sensor Circuit (Bank 1 Sensor 3)
Powertrain system Generic code P24xx codes Check engine light
What P242A means
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.
P242A at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P242A
- MIL on
- Particulate filter regeneration or DEF dosing suspended
- Implausible or missing value for sensor 3 in the scan tool
Common causes of P242A
- Most 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)
- Less likelyOn Ford diesels, sensor reading deviating from the exhaust temperature model
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Egt sensor b1s3
What each part of P242A means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 2A | The exact fault in that area. |
What to do next
- Note P242A and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P242A
What does P242A mean?
P242A means "Exhaust Gas Temperature Sensor Circuit (Bank 1 Sensor 3)". P242A is the general circuit code for the third exhaust temperature probe on bank 1. It is a generic code, so it means the same on every make.
Is it safe to drive with P242A?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P242A fail an emissions test?
Yes, it can. P242A is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P242A to fix?
Difficulty: medium. A typical repair takes 0.3 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P242A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.