QuestionQUESTION: I had emailed before. My red battery warning light on the dash is staying on, as is the check engine light. The overhead display which shows temperature and direction reads SC, but all the other features work fine. My mechanic tested the battery,and alternator and replaced the computer, but the readout does not clear. Any advice would be appreciated.
Thanks
Joyce
ANSWER: Hi Joyce,
That is helpful.
The 'SC' on the overhead console means "short circuit" and suggests checking the connection between the sensor (which is located at the front, behind the bumper on the radiator closure panel) and the body computer (which is under the dash behind the fuse box) to see if one of its wires is exposed and touching a metal piece connected to the chassis.
Because both the check engine light and the battery light (though it appears there is nothing wrong with the charging system according to the mechanic) are "on", I would suggest that you get a readout of the powertrain controller memory to find if their are any fault codes stored in its memory which would shed some light on why this is the case. If there is an Autzone parts store nearby they will often do a readout for free. Or an independent shop will do it for under $40. Ask for the 4-digit fault code numbers, what they mean, what they suggest to do, and the cost. Then write me back with the results and we can compare that to the manual. It could be that the fault is in the instrument cluster itself (false warning lights) but I would check for any fault codes.
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi Roland. The fault code came up P1493, and he said that was a battery temperature sensor. The temp of the battery has been normal each time he checked, and they tried swapping out my computer and it did not clear the readout. Thanks again for your time - I am really grateful!
Joyce
AnswerHi Joyce,
OK, it appears that the temperature sensor that checks on the environmental temperature is not working or the wiring from it to the body computer is open/shorted. The sensor info is used to decide how much current/voltage should be put out by the alternator which is based upon the temperature. Thus, your charging light could be on because of this malfunction. The sensor is located behind the grill at the top edge, it has a gray plug and two wires (dark blue/gray and violet/light green). You access it through an oblong opening in front of the radiator after you open the hood. Those two wires go to pins 10 and 5, respectively, of the body computer's white plug (the computer is on the back side of the fuse box under the dash). The mechanic should check the connections between the sensor plug and the body computer, or simply replace the ambient sensor if it is not too expensive compared to checking the wiring for continuity or shorting to ground. (Call a dealer parts counter and ask for the cost of the sensor).
A Chrysler dealer can troubleshoot the wiring using a diagnostic readout box, or the shop can check to make sure that the wire on pin 5 (violet/light green) is not shorted to ground as that is the signal wire, once they have disconnected the sensor from its plug. Also measure the resistance between the two wires with the white plug unplugged and sensor removed, to be sure they aren't shorted together.
If that doesn't reveal a problem, then try replacing the sensor. You might want to have a Chrysler shop do the test with their reader as this could save labor time, if it is a competent shop. Again, just replacing the sensor yourself could possibly solve the problem with no labor cost.
Once you fix the issue, the charging light should ideally go off.
Roland
