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Hello, my name is***** the check engine light come on for bulb test? Are you setting any codes? Thanks.
Do you have scan tool to monitor cam sensor and crank sensor signal? The PCM requires crank signal to enable main relay which sends power to coil. The cam/crank sensors use the same 5v circuit so if cam sensor is acting up it can cause crank signal to have problems.
Sometimes aftermarket sensors can cause problems if you didn't buy from Jeep. Next step is to check wiring. Check the voltage on the orange wire at the Camshaft Position (CMP) sensor. If voltage is less than 7 volts, unplug the Crankshaft Position (CKP) sensor, cycle the key off and on again and recheck. If the voltage is now at least 7 volts, reconnect the CKP sensor. If the voltage goes down again, the CKP sensor is shorted. The Vehicle Speed Sensor (VSS) could also be shorting out the 8 volt power supply. If 8v is good then next step is checking wiring between cam/crank sensors and PCM, each wire should have under 5 ohms resistance, if good replace the PCM. Brown/yellow wires get ground from PCM and signal wires send 0-5v square wav to PCM. If wiring tests good and sensors are sending good signal then replace PCM. Here is a wire diagram to help with testing, let me know if there is anything else I can do to help. Thanks.-https://www.dropbox.com/s/qt0hc5z2vkmlxzh/ck.png?dl=0-
The ASD relay only activates when PCM see's crank signal. I'm assuming ASD relay is not activating. Let me know, thanks.
If you remove relay, jump pin 87 to pin 30 that should force voltage to coil which will at least prove that part of wiring is good. Let me know, thanks.
Here are diagrams.
What pin # *****'t light up test light? That would point toward poor connection.
One pin should have power only with key on and one pin should have power at all times. Which one of the two is having the testlight problem.?
Unplug PCM and ground dark blue/yellow wire at pin C3 with key on. This should activate the ASD relay putting power at coil, if so it sounds like your PCM has failed. let m know how it goes, thanks.
Replace the ASD relay if you haven't already and let me know if that helps
Ok, lets try and figure out why the test light won't light. This gets power from 10 amp fuse 11 on interior. Check to see if test light will turn on when touching fuse with key on.
Fuse gets power from ignition switch via dark blue wire. Next step is accessing wire at ignition switch to see if it can turn light on. Let me know, thanks.
The ignition switch feeds the fuse which feeds the relay. That is why I was having you do test at ignition switch so we could se where problem was and repair.
Does vehicle start when jumping pin 87 to pin 30?
Remove/reinsert fuse 3 under hood which is a 30 amp incase it has a bad connection. Let me know, thanks.
Hello! Different expert here. Did you still need help? If so, please accept my offer and call me so we can talk over the phone.