2003 jeep grand cherokee check engine light P1499 P1685
P1499 is referring to hydraulic fan control solenoid. It's for your cooling fan. All you need to do is replace the hydraulic fan solenoid. P1685 is referring to the anti theft system (SKIM) at some point it seen an invalid key code. I would do a hard reset. Take both battery terminals off and touch together for about 30 seconds and then reattach. Should reset code 1685.
You never want to touch the battery cables together, you would be creating a direct short in the electrical system. Any residual voltage built up could blow the computer or other electrical components. P1499 JEEP - Hydraulic Cooling Fan Solenoid Circuit Condition...Possible causes: Faulty Hydraulic Cooling Fan Hydraulic, Cooling Fan harness is open or shorted, Hydraulic Cooling Fan poor electrical connection......P1685 JEEP - Invalid SKIM Key...Possible causes: Reprogram Smart Key Immobilizer Module (SKIM) key, Faulty Immobilizer Key, Faulty Immobilizer Module...The P1685 code means that there is something wrong with either your ignition key or your Immobilizer Module.
Or three back to back key cycles with multiple keys. Its a Chrysler product. I have fixed numerous Chrysler products with a hard reset to computer. Doing a hard reset on this 2003 jeep may clear up both issues that it is experiencing. Touching terminals together on a Chrysler made product kills residual voltage. That is the main problem with Chrysler computers and there integrated systems they still continue to use today. I should have reworded what I said because any time a part such as the the cooling. Always check fuses and relays. If a Chrysler will not crank. The first thing I check is the ads relay. If that relay doesn't power up. You have a shit computer.
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