Diagnostic Aids

Solenoid coil resistance must measure more than 20 ohms. A lower resistance value will cause early failure of the ECM driver. Check the solenoid coil resistance of all ECM controlled solenoids and relays, before installing replacement ECM. Replace any solenoid or relay that measures less than 20 ohms resistance.

Fig 1: TCC Electrical Diagnosis - Diesel Electronic Control System Flowchart