Electronic Control Module (ECM)

IMPORTANT NOTE!
The Engine Control Module (ECM) is a highly efficient component and replacement is rarely needed. ECM failure is usually caused by another component. If an ECM is found to be faulty, be sure to inspect all input and output circuits prior to installation of the the new ECM. Installing a new ECM without correcting another possible problem will cause repeated ECM failure.

ECM TESTING
The ECM is a transistorized computer component. There are no specific testing procedures. Diagnostic codes 51 indicate a faulty ECM or EEPROM. If this code is present, check that all ECM connections are good, clear memory and recheck. If code 51 reappears, replace the ECM.

Always think of the ECM as the last possible source of a problem. Rarely do they fail.