has replacing the ECU correct the over chargering of the battery?

Asked by electricaproblems Aug 12, 2015 at 10:59 AM about the 2004 Dodge Intrepid ES FWD

Question type: Maintenance & Repair

I have had a problem with my 2004 Dodge Intrepid battery?charging system, the
battery and the alternator have been replaced three times each without the problem
being solved. My mechanic thinks that the ECU might be bad. And so the question is,
will replacing the ECU actually correct this continuing problem? When the car is
running at idle it is charging at 12.5 to 13.0 volts with a low battery, when the
accelorator in pushed it shows 17 to 20 volts. this causes the battery to overcharge
and fail.This has happened three times at least. I have read on the internet that "04
intrepid's are "known to have electrical problems".  How can I be sure that changing
the ECU is the answer? I've had two different mechanic's work on this with the same
conclusion, I don't want to keep putting money in a car that is a lemon or can't be
fixed!!!!

1 Answer

188,355

Just read on how to test the electric system on your car. With no Charging System No Code Test... Battery condition must be verified prior to this test. 1. Inspect the generator belt tension and condition. 2. Start engine. 3. With the scan tool set the engine speed to 1600 rpm for 30 seconds. 4. With the scan tool return the engine to idle speed and read codes. 5. If there are any charging system trouble codes present, perform the DTC Test. 6. If there are no charging system trouble codes present: NOTE The voltage should cycle from low to high at the generator field driver terminal. Turn ignition on (engine off ). With the scan tool actuate the generator field. With a voltmeter backprobe the generator field DR terminal at the back of the generator. A. While monitoring the scan tool, wiggle the field terminals back to the PCM and the ASD relay: If there is any interruption in the normal cycle between low and high voltage, repair the wire where wiggling interrupted the voltage cycle. If there is no interruption in the normal cycle between low and high voltage, with the scan tool read trouble codes and perform DTC Test if there are any charging system trouble codes. B. If there are no charging system trouble codes present: If there are no charging system trouble codes present: CAUTION Ensure all wires are clear of the engine-s moving parts. Connect a voltmeter between the generator (12 V) B(+) terminal and the battery (+) side. Start the engine. Verify if the voltage is above 0.1 volt, if the voltage is above 0.1 volt, repair the generator ground for high resistance, generator case to battery (-) side. CAUTION Ensure all wires are clear of the engine-s moving parts. Connect a voltmeter between the generator (12 V) B(+) terminal and the battery (+) side. Start the engine. Verify if the voltage is above 0.1 volt, if the voltage is above 0.1 volt, repair the generator ground for high resistance, generator case to battery (-) side. C. If the voltage is below 0.1 volt: With the scan tool read the battery voltage and record. Using a voltmeter measure the battery voltage, record second voltage reading. Compare the two voltage readings. If there is a voltage difference less than one volt the test is complete. D. If there is a voltage difference greater than one volt: With the ignition key off , disconnect the Power Train Control Module. With a voltmeter, measure the fused B (+) at the PCM. If the voltage is within one volt of the scan tool recorded reading, repair the B (+) circuit for high resistance between the PCM cavity 46 and the battery. If the voltage is not within one volt of the scan tool recorded reading, replace the Power Train Control Module

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