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Need an explanation in the differences between the 1999 and 2000 PCM harness? Asked by Jeeperz6622 a

Discussion in 'Electrical' started by Jeeperz6622, Feb 21, 2021.

  1. Feb 21, 2021 at 11:40 AM

    Jeeperz6622 [OP] New Member

    Feb 21, 2021
    First Name:
    1999 Jeep Grand Cherokee Limited 4.7
    In process of complete restoration.
    I have a 1999 WJ Limited 4.7 that has a decent body and only 50,000 miles on the transmission and transfer case. I also have a 2000 WJ Limited 4.7 from the rustbelt with a trashed body. I am replacing the complete wiring harness, interior, dash, HVAC and all electronics of the 1999 WJ with the 2000 wiring harness, interior, dash, HVAC and all electronics. I am doing a complete swap of the wiring harness due to the 1999 wiring harness being hacked-up quite badly. I am almost done with the complete 4.7 engine rebuild but before I reinstall the rebuilt motor, I am wanting to repaint the engine compartment and finish up the wiring harness installation.

    My question is that I have noticed a difference between the two harnesses. The PCM/TCM harness from the 2000 WJ has an additional connector (indicated by the red tape). this additional connector (I believe) goes to the transmission but I do not remember to exactly where and I cannot find the mating connector.

    I have read somewhere there are differences electronically between the 1999 45RFE and the 2000 45RFE. Can someone explain exactly what these differences are and what has to be modified in order to utilize the 2000 PCM harness in the 1999 WJ? Additionally, is this additional connector (pictured below) part of the differences between the two 45RFEs?

    Thanks in advance for your reply

    Last edited: Feb 22, 2021
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