U1026 Code: Meaning, Causes, and Symptoms | OBD2 Codes

U1026 – SCP Invalid or Missing Data for Engine RPM


U1026 Possible Symptoms


Engine Light ON (or Service Engine Soon Warning Light),Service 4WD Light ON,Engine cranks but may not start 鈥 may be intermittent,May / may not shift from 2-wheel drive to 4-wheel drive / 4-wheel drive to 2-wheel drive,May or may not be able to communicate with a scan tool / depends on problem


U1026 Possible Causes


Faulty / intermittent ignition switch connections,J1850 / SCP Bus wiring intermittently open, shorted to power or ground,Faulty / intermittent connection at the Powertrain Control Module (PCM),Faulty / intermittent connection at the Instrument Panel Cluster (IPC),Faulty / intermittent connection at the Transfer Case Control Module (TCCM)


U1026 Description


This is a manufacturer specific fault code and can be used for several different faults, depending upon what the manufacturer wants to use it for. The Powertrain Control Module (PCM) communicates over the Serial Communication Protocol (SCP) bus network, or J1850 bus. This is a medium-speed bus communication system and is fault tolerant, which means any type of intermittent/loose connection at these controllers will cause this code to set in memory, but will still operate, provided a data path is available. When the PCM is unable to communicate with any other controller at any time while the ignition switch is turned on, code U1026 will set. This is the typical reason for this code to set.