Help!! 85 22RE 4x4 code 13 - knock control CPU

[ballzer5169]

Just finished up a rear main seal replacement (pulled tranny). Checked compression before firing up and everything good. Coil wire arked out while checking #3 for 4-5 cranks. Fired ip and runs good. Now check engine lights on constantly. Code 13-knock control CPU. Can't figure it out.

 

[Sam Stewart]

According to TIS code 13 is for RPM signal. It looks like it's taken from the distributor/igniter. It says the code is triggered when there is no "Ne" signal above 1500 RPM.

 

[ballzer5169]

Code 13 would be the case if this was an 86 or newer, but my 85 have codes 1-13 only. 13 being - Knock Control CPU. Perhaps the computers changed sometime in 85 but i do know this truck has the early codes.