ECM Code 21 Ignition Signal Primary ???

[DrSumtingWong]

Anyone here familiar with ECM Code 21 Ignition Signal Primary? Cars runs extremely rich and really rough at an idle. Its drivable but power is definetely missing. That code 21 also had friends, codes 12 (MAF) and 34 (Knock Sens.).This all started after a light front end collision. Someone @ Nissan Dealer told me injectors but i just cant believe thats the case. Ive replaced MAF and Ignition Module.. no changes.

[jserrano]

I am somewhat familiar with code 21. But I would start by clearing out the ECM codes and see what returns. I am sure that the KS code will come back.

The code 21 is like it say, there is a problem on the primary side of the ignition; power transistor, ignition coil, resistor/condensor, and quite possibly the distributor itself.

A scope check of the ignition signal on the primary igntion side of the coil should be able to tell you what is going on.

[Raxephon]

Sometimes if the connectors aren't pushed together completely you can get a code 21.

I would start there and work my way up.