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2012 Jeep Liberty Limited 3.7L Not charging new batt/alternator HELP
gonzalezaamg28 wrote: Hello, I am working on a 2012 Jeep Liberty Limited 3.7L that was brought to me due to not charging. The customer advised me that the vehicle was not cranking over so he thought it was the battery that had gone bad. The customer put a new battery and it did not fix the problem. The customer then took the vehicle over to a shop where a brand new alternator was put in and it still did not fix the problem.
The first thing I did was hook up my snap on solus edge scan tool and run a code scan. I got a bunch of codes in reference to a low voltage from several of the body modules. I then opened up the Mitchell repair manual and followed the prcedures for the DTC P0562. Everything seemed to be okay. I then believed that the PCM was bad because it was not signaling the alternator to engage.
I wanted to be sure before telling the customer to replace a 400 dollar part so I continued to check the wiring. I found something that was odd. The batt sense wire that comes off the back of the alternator is supposed to tell the computer how much voltage the battery has. When a specific voltage is met, the the computer then sends a signal to the alternator to activate it (PWM). When I hooked up my volt meter to battery ground and battery positive I got a reading of 12.5 volts. I then moved my positive lead to the batt sense wire behind the alternator and got a reading of around 9.5 volts. This seemed odd because the battery was fully charged. This reading was with the key on. I then noticed that when I would disconnect the batt negative and reconnect it the voltage would then read 12.5 volts. As soon as I would turn the key forward, the PCM it would then read the 9.5. There was clearly some type of voltage drop. I started to check the PCM connector where the batt sense is connected to and the other wires on the connector. I found that the can bus (-) and can bus (+) had continuity with each other. I also noticed that the shielding was browned as if they were or had gotten hot. No fuses are burned on the vehicle. and the vehicle turns on fine. I tried tracing these 2 wires down, but had no luck. IM STUCK ANY IDEAS? Am I doing something wrong?
Can you please repost the link the message above I've been trying to open it can't perhaps it's user error but it just tells me the page doesn't exist much thank you
Auyloks wrote: Can you please repost the link the message above I've been trying to open it can't perhaps it's user error but it just tells me the page doesn't exist much thank you
Unfortunately, Remy decided to take that page down. Which is a real shame given the quality material they had up. You can try exploring the Printable Material and Training sections, but they're not nearly as good.
EDIT: I took the link off the pinned service info thread. Thanks for the reminder.
Last edit: 3 years 3 months ago by Tyler. Reason: reasons
Which is a real shame given the quality material they had up. You can try exploring the Printable Material and Training sections, but they're not nearly as good.