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.
Narrow by vehicle
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
6Original wording in English
VOLVO
Engine Brake - Diagnostic Trouble Code (DTC) P1021-11 Volvo Compression Brake (VCB) Control Circuit Short To Ground - US17+OBD16 Through US17+OBD19 Emissions, Model Years 2018 To 2020
VOLVO
Engine Brake - Diagnostic Trouble Code (DTC) P1021-11 Volvo Compression Brake (VCB) Control Circuit Short To Ground - US17+OBD16 Through US17+OBD19 Emissions, Model Years 2018 To 2020
MACK
Engine Brake - Diagnostic Trouble Code (DTC) P1021-11 Volvo Compression Brake (VCB) Control Circuit Short To Ground - US17+OBD16 Through US17+OBD19 Emissions, Model Years 2018 To 2020
HONDA
PRODUCT UPDATE: ECM UPDATE TO PREVENT CATALYST DTC P0420 AND/OR VPS DTC P1021, MCM UPDATE TO CURRENT SPECIFICATIONS. *TT
Check vehicle applicability
46A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| Honda | CIVIC ↗ | 2005 |
| Honda | CIVIC ↗ | 2004 |
| Honda | CIVIC ↗ | 2003 |
| Mack | ANTHEM (AN) ↗ | 2020 |
| Mack | ANTHEM (AN) ↗ | 2019 |
| Mack | ANTHEM (AN) ↗ | 2018 |
| Mack | CHU ↗ | 2018 |
| Mack | CXU ↗ | 2018 |
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.