What does code P1604 mean?

Q: What does code P1604 mean?

Loss Of IPC Serial Data. P1604 on a GM vehicle means the engine control module (ECM) has lost serial data communication with the instrument panel cluster (IPC) over the class 2 data bus. The ECM monitors the data bus for regular status messages from the IPC, and when those messages stop arriving for a calibrated period, it stores this code and may command the cluster to default or illuminate warning lamps.

DTC codes / GM codes / P1604

P1604 · GMLoss Of IPC Serial Data

P1604 on a GM vehicle means the engine control module (ECM) has lost serial data communication with the instrument panel cluster (IPC) over the class 2 data bus. The ECM monitors the data bus for regular status messages from the IPC, and when those messages stop arriving for a calibrated period, it stores this code and may command the cluster to default or illuminate warning lamps.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaComputer and output circuits

Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.