C2123 Engine Trouble Code
What is C2123?
With C2123, you may drive for several weeks with a malfunctioning MAF sensor, but expect decreased fuel economy and eventual stalling. Shop replacement costs $240–$400 depending on vehicle. The labour is straightforward, with most cost from the part itself.
Code Information
| Code Type: | OBD-II Chassis (C) Trouble Code |
| System: | Chassis |
| Code: | C2123 |
C2123 Symptoms
Check Engine Light
Illuminated dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration
Starting Problems
Difficulty starting the engine
C2123 Code Structure
Understanding what each digit means in the C2123 chassis trouble code:
| C | 2 | 1 | 2 | 3 |
|---|---|---|---|---|
| Chassis Code | Fuel And Air Metering (Injector Circuit Malfunctions Only) | Fuel Rail/System Pressure — Too High | Turbocharger Boost Sensor A Circuit Low | Exhaust Gas Recirculation Sensor B Circuit High |
How to Fix C2123
Diagnostic Steps:
Poor running symptoms align with MAP sensor malfunction. In some cases, a faulty MAP sensor will not trigger a code. The issue may represent separate wiring concerns requiring individual diagnosis.
Repair Solution:
Excessive air inflow may result from vacuum leaks, dirty sensors, or EGR valves not closing properly. Insufficient fuel can stem from dirty injectors, clogged filters, weak fuel pump, or leaking pressure regulator.
Technical Notes:
C2123 DTCs can be triggered by upstream issues. For example, a dirty MAF sensor may cause incorrect fuel-trim adjustments, leading oxygen sensors to report mixture problems. Address root causes first.
C2123 Description
C2123 engine trouble code is related to Exhaust Gas Recirculation Sensor B Circuit High.
Main Cause
The primary reason for C2123 OBD-II Engine Trouble Code is: Fuel Rail/System Pressure — Too High.