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Dodge Repair/'99 Concorde no start: code P1685


Mr Finston, I got the codes: P1684 & P1685
Thank you

History:QUESTION: 1999 Concorde LXi. New battery, starter, alternator, spark plugs, fuel pump, crank sensor. If I spray starting fluid it will start. I was told that it could be the BCM under the dash. Engine light is on. Also only stays in Park. I was told a cable to the gear shift could have accidently been disconnected underneath while installing starter? I will really appreciate your opinion.

ANSWER: Hi Leon,
When you say only stays in Park, I assume that is when you have successfully started the engine, correct. And when that is the case, the shift lever will move but the trans does not disconnect the parking pawl and the vehicle can not be moved by hand, correct? If those are true then it may be that there is a problem with the gear shift connection to the transmission.
You can observe the transmission shift cable function where it is located on the driver's side of the transmission where it attached to a vertical rod about which a lever should move as a helper shifts the gear shifter in the cabin.
But setting that aside, on the starting problem have you tried to get fault codes? Turn the ignition switch: "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer to see the mileage reading to be replaced by a 4-digit number preceded by a P. Let me know that number(s) and we'll go from there. Tell me which size (L) you have.
Did you do all the parts replacements, or which were done by a shop?
Please read the PS (below) and respond to it.

Answer to this question:
Hi Leon,
The 1684 means the battery was disconnected or discharged recently (within the past 50-100 key starts, so that is expected given the history of replacing the battery.
The 1685 says that there is an issue with the security key immobilizer system, which is why there is a bulge in the "head" of your ignition key and the system which senses it when you put it in the ignition switch. Have you changed out the ignition key recently without getting it "programmed" so as to be recognized? If not, then possibly this issue is with a loose or open connection of the "antenna" wire that is a ring, that you see that is looped around the ignition switch, such that it is not sensing the key. If that happens, then the engine will start and run for about 3 seconds and then be shut off. Is that what is happening when you start the car?
If so, take a look at that loop and then to see its connection to the module you would remove the tilt lever screw, then the tilt lever, then remove the upper and lower steering column covers (screws on the underside of the column. Then you can examine that 'antenna's' connections. Check fuses 14 and 19 in the box behind the left end cap of the dash which are needed to power the sentry key module.
Let me know what you find or whether you are using a different ignition key than the usual one.
The sentry key module is attached to and controlled by the bcm but consider the key and antenna issue first.
If you do want to ask another question, please do a "follow up" so that the history of our discussion is shown.
Please rate both of my answers and where you see the question about a nomination of me to be expert of the month give a "yes" answer.

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Roland Finston


Get a Free Fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

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