Code 12, 13 - Rpm Signal

Code 12 is caused by loss of "NE" or "G" signal from distributor to ECM for at least 2 seconds after starter signal is received at ECM. Check distributor and ignition system components. See SYSTEM/COMPONENT TESTS article in this section. Ensure starter signal exists at ECM. See CODE 43/TEST NO. 8 - STARTER SIGNAL test procedures in this article.

Code 13 is caused by loss of "NE" signal from distributor to ECM when engine RPM exceeds 1000 RPM. Check distributor and ignition system components. See SYSTEM/COMPONENT TESTS article in this section.