DTC 12 & 13 - Rpm Signal

Code 12 is caused by loss of "G" or "NE" signal from distributor to ECM for at least 2 second after starter signal is received at ECM. Check distributor and ignition system components. See SYSTEM & COMPONENT TESTING article. Ensure starter signal exists at ECM. See DTC 43 - STARTER SIGNAL .

Code 13 is caused by loss of "NE" signal from distributor to ECM when engine RPM exceeds 1500 RPM.Check distributor and ignition system components. See SYSTEM & COMPONENT TESTING article.