TCM-ECM Communication Fault
2007-2016 Volvo S80 3.2L I6
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
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1618 on Other Vehicles
Common Questions
What does code P1618 mean on a 2007-2016 Volvo S80?
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 S80?
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 2007-2016 Volvo S80?
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.