P2034 is the general electrical fault of the second exhaust temperature sensor on bank 2, so it only appears where the second bank has its own measuring point downstream. GM does not use it: the 2018 diesel tables number every exhaust temperature sensor on bank 1 (P0545/P0546, P2032/P2033, P242C/P242D, P2470/P2471), as one aftertreatment line serves the whole engine. Deutz assigns P2034 on its EMR L1 engine controller (industrial engines, list of November 2022) to the second temperature sensor upstream of the SCR catalyst, with failure-type bytes: -13 open, -11 shorted to ground, -12 shorted to battery, -F0 ground fault, -1C supply out of range. Others split low and high readings into P2035 and P2036. With the reading lost, temperature-dependent DEF dosing or filter regeneration is usually limited.
Medium severity. Can I keep driving?If the light is on steadily, take a highway drive or go to a repair shop soon. If the car is in limp mode or the light is flashing, do not push the engine.
Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.
Symptoms
- Engine warning lamp on
- DEF dosing or particulate filter regeneration restricted
- Engine power reduced on some applications
Most likely causes
- Sensor lead open or shorted where it runs along the hot exhaust
- Sensing element failed after many heat cycles
- Water or corrosion in the sensor connector
- Sensor ground or supply from the control unit faulty
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P2034 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 0: Subsystem depends on the code range
- 34: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2034?
If the light is on steadily, take a highway drive or go to a repair shop soon. If the car is in limp mode or the light is flashing, do not push the engine.
What causes code P2034?
The most common causes are: sensor lead open or shorted where it runs along the hot exhaust; sensing element failed after many heat cycles; water or corrosion in the sensor connector.
Related codes
- P2035Exhaust Gas Temperature Sensor Circuit Low (Bank 2 Sensor 2)
- P2036Exhaust Gas Temperature Sensor Circuit High (Bank 2 Sensor 2)
- P2086Exhaust Gas Temperature Sensor Circuit Range/Performance (Bank 2 Sensor 2)
- P2087Exhaust Gas Temperature Sensor Circuit Intermittent (Bank 2 Sensor 2)
- P2031Exhaust Gas Temperature Sensor Circuit (Bank 1 Sensor 2)
Sources
- serdia.deutz.com: DTCList EMRL1 MainECU EN
- gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.