P1840

JATCO Fault P1840 - CAN BUS Malfunction

P1840 - CAN bus malfunction.

Possible causes:
1. Open Circuit CAN BUS
2. Open Circuit CAN BUS.
3. Connectors CAN BUS.
4. Instrument pack problem.
5. ECM Problem.
6. ATCU Problem.

1. Open Circuit CAN BUS
OPEN_CIRCUIT
Check resistance > 1M Ohms.

2. Open Circuit CAN BUS.
OPEN_CIRCUIT
Check resistance > 1M Ohms.

3. Connectors CAN BUS.
CONNECTOR
Check for connector not correctly latched, backed out pins, damaged pins, corroded pins

4. Instrument pack problem.
- The CAN BUS consists of two screened cables which connect several ECUs together allowing them to exchange information digitally at high speed. Failure of the CAN BUS will result in various ECUs setting fault codes and entering a fail-safe mode of operation.
- The failure of the CAN BUS can be caused by problems with any of the wiring or connectors which make up the bus or failure of an ECU connected to the bus (ECU faults are the least likely cause of failure).
- As the instrument pack handles CAN information from the ECUs the best place to diagnose CAN problems is by using the instrument pack diagnostic.

5. ECM Problem.
- The CAN BUS consists of two screened cables which connect several ECUs together allowing them to exchange information digitally at high speed. Failure of the CAN BUS will result in various ECUs setting fault codes and entering a fail-safe mode of operation.
- The failure of the CAN BUS can be caused by problems with any of the wiring or connectors which make up the bus or failure of an ECU connected to the bus (ECU faults are the least likely cause of failure).
- As the instrument pack handles CAN information from the ECUs the best place to diagnose CAN problems is by using the instrument pack diagnostic.

6. ATCU Problem.
- The CAN BUS consists of two screened cables which connect several ECUs together allowing them to exchange information digitally at high speed. Failure of the CAN BUS will result in various ECUs setting fault codes and entering a fail-safe mode of operation.
- The failure of the CAN BUS can be caused by problems with any of the wiring or connectors which make up the bus or failure of an ECU connected to the bus (ECU faults are the least likely cause of failure).
- As the instrument pack handles CAN information from the ECUs the best place to diagnose CAN problems is by using the instrument pack diagnostic.