I hope someone can help me. I don't have any spark at the coil on #1 & #4 cylinders. I have replaced the coil, wires and plugs still no spark.
Can someone help?
The ECM indeed supplies the ground for the ignition coils, but it would be wise to check the voltage side first. The voltage to the coils is switched via the ASD relay ( auto shut down). When ignition is switched to run, the ASD relay will be powered, but when not started, it will fall off after some seconds. If power is available there, you could measure the ground wire from the coil to the ECM for continuity. If this also is ok, then most probably the ECM is faulty.
Your jeep has two ASD´s? Eventhough the relay is fine, it doesn´t say that the wiring to the coil is. It would be a pitty to change the ECM to find out that the problem is wiring related. Only by measuring the voltage at the coil you can be sure about that.