Reference meaning
What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
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A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Scan worksheet →Manufacturer communications
25Original wording in English
CHEVROLET, GMC
This service bulletin provides a service procedure to correct a customer concern of the Malfunction Indicator Lamp (MIL) Illuminated - DTC P062F, P040B, P041B, P0422, P060C, P062B, P1428, P142A, P20EE, P20FE, P22F9, P244A, and/or P244B Set.
CHEVROLET, GMC
This technical bulletin provides repair information to correct a customer concern of Service Engine Soon Lamp being illuminated. They may also comment on multiple transmission issues including harsh or delayed shifts, slip, surge, shudder, noise, whine, growl, shake and/or vibration. As well as the exhaust brake not working or t…
CHEVROLET, GMC
This Preliminary information provides information to the technician Direction for when DTC P0422 Sets on a 2024 Vehicle with the 6.6L L5P engine.
CHEVROLET, GMC
This technical bulletin provides repair information to correct a customer concern of Service Engine Soon Lamp being illuminated with DTCs P2002, P2463, P2459, P144E, P0421, P0422, P0106 P20EE, P129F, P16F3, P20FF, P226D, P249D, P249E, P11CC and / or P11D5. They may also comment on multiple transmission issues including harsh or …
Check vehicle applicability
234A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Audi | A6 ↗ | 2000 |
| Audi | A8 ↗ | 2000 |
| Chevrolet | SILVERADO 1500 ↗ | 2024 |
| Chevrolet | SILVERADO 2500 ↗ | 2024 |
| Chevrolet | SILVERADO 2500 ↗ | 2020 |
| Chevrolet | SILVERADO 3500 ↗ | 2024 |
| Chevrolet | SILVERADO 3500 ↗ | 2020 |
| GMC | SIERRA 1500 ↗ | 2024 |
Code meaning and manufacturer information
Original wording in English · Historical directory labels; manufacturer applicability has not been established for every entry.
Main Catalyst Efficiency Below Threshold (Bank 1)
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.