TCM Serial Communication Problem
2015-2021 Kia Sedona 3.3L V6
Description
The PCM has detected a serial communication problem with the Transmission Control Module. Data exchange between the PCM and TCM is interrupted or corrupted, preventing coordinated powertrain operation.
Symptoms
- Check Engine Light
- Transmission in limp mode
- Harsh shifting
- No upshifts or downshifts
- Cruise control inoperative
Common Causes
- Faulty TCM
- CAN bus wiring damage
- Corroded CAN bus connector
- TCM power or ground issue
- PCM CAN bus driver failure
Diagnostic Steps
- Check TCM power supply and ground connections
- Inspect CAN bus wiring between PCM and TCM
- Test CAN bus resistance (approximately 60 ohms between CAN-H and CAN-L)
- Attempt to communicate with TCM using scan tool
- Check for TCM-specific DTCs
Repair Notes
Repair CAN bus wiring or connectors; replace the TCM if it has failed internally.
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
P1602 on Other Vehicles
Common Questions
What does code P1602 mean on a 2015-2021 Kia Sedona?
P1602 stands for "TCM Serial Communication Problem". The PCM has detected a serial communication problem with the Transmission Control Module. Data exchange between the PCM and TCM is interrupted or corrupted, preventing coordinated powertrain operation.
What are the symptoms of P1602 on a Kia Sedona?
Common symptoms of P1602 include: Check Engine Light, Transmission in limp mode, Harsh shifting, No upshifts or downshifts, Cruise control inoperative.
What causes P1602 on a 2015-2021 Kia Sedona?
Common causes of P1602 include: Faulty TCM, CAN bus wiring damage, Corroded CAN bus connector, TCM power or ground issue, PCM CAN bus driver failure.