What does code P1638 mean?

Q: What does code P1638 mean?

CAN Link ECM INSTM Circuit Network. P1638 on a Jaguar indicates that the engine control module (ECM) has lost or corrupted the CAN (Controller Area Network) link to the instrument cluster module, which Jaguar refers to as the INSTM. The ECM expects a continuous data exchange with the cluster for sharing vehicle speed, engine temperature, and warning lamp status, and it sets this code when the expected CAN messages are missing or invalid.

DTC codes / Jaguar codes / P1638

P1638 · JaguarCAN Link ECM INSTM Circuit Network

P1638 on a Jaguar indicates that the engine control module (ECM) has lost or corrupted the CAN (Controller Area Network) link to the instrument cluster module, which Jaguar refers to as the INSTM. The ECM expects a continuous data exchange with the cluster for sharing vehicle speed, engine temperature, and warning lamp status, and it sets this code when the expected CAN messages are missing or invalid.

SystemPowertrain

Code typeJaguar specific

SeverityMedium

Fix difficultyProfessional

AreaComputer and output circuits

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