TCM-ECM Communication Fault
2024-2024 Volvo EX30 Single Motor RWD
Description
The ECM detected a communication fault with the Transmission Control Module (TCM). The CAN bus communication between the engine and transmission controllers is disrupted or unreliable.
Symptoms
- Check Engine Light
- Transmission may enter limp mode
- Harsh or incorrect shifting
- Transmission warning light
- Reduced power
Common Causes
- CAN bus wiring fault between ECM and TCM
- TCM failure
- ECM CAN driver failure
- Corroded CAN connector
- CAN bus termination resistor fault
Diagnostic Steps
- Check CAN bus communication with diagnostic tool
- Test CAN High and CAN Low signals
- Inspect CAN bus wiring between ECM and TCM
- Test CAN termination resistance
- Check TCM power and ground
Repair Notes
Repair CAN bus wiring or replace the faulty module (ECM or TCM).
Related Codes
Other Powertrain Codes
- P0070Ambient Air Temperature Sensor Circuit
- P0071Ambient Air Temperature Sensor Range/Performance
- P0072Ambient Air Temperature Sensor Circuit Low
- P0073Ambient Air Temperature Sensor Circuit High
- P0115Engine Coolant Temperature (ECT) Sensor 1 Circuit
- P0116ECT Sensor 1 Circuit Range/Performance
- P0117ECT Sensor 1 Circuit Low Input
- P0118ECT Sensor 1 Circuit High Input
- P0119ECT Sensor 1 Circuit Intermittent
- P0125Insufficient Coolant Temperature for Closed Loop Fuel Control
P1618 on Other Vehicles
Common Questions
What does code P1618 mean on a 2024-2024 Volvo EX30?
P1618 stands for "TCM-ECM Communication Fault". The ECM detected a communication fault with the Transmission Control Module (TCM). The CAN bus communication between the engine and transmission controllers is disrupted or unreliable.
What are the symptoms of P1618 on a Volvo EX30?
Common symptoms of P1618 include: Check Engine Light, Transmission may enter limp mode, Harsh or incorrect shifting, Transmission warning light, Reduced power.
What causes P1618 on a 2024-2024 Volvo EX30?
Common causes of P1618 include: CAN bus wiring fault between ECM and TCM, TCM failure, ECM CAN driver failure, Corroded CAN connector, CAN bus termination resistor fault.