> Main > Gas Index > DIY Repair > OBD1 codes > Fault 44
Fault Code 44 - Battery temp sensor volts out of range

Visit Geno's Garage
for Truck accessories.
Geno's Garage Truck Accessories


Code 44 is set by a problem in the charging system. It could indicate an over charge, undercharge, bad relay, bad battery temperature sensor, or shorted battery cell. NOTE: The PCM uses an air-cooled resistor to sense the incoming air temperature. This information is fed to the logic module and is used to control the duty cycle of the field current in the alternator. The battery voltage is sensed by the logic module -- there is an internal takeoff from the wire feeding the NVRAM keep-alive power circuit which is fed to a voltage comparator. So...if you lose the feed to keep RAM information stored when the engine's off, you also lose battery voltage sensing.

1.   Turn the ignition switch OFF use a digital voltmeter to measure the voltage at the battery terminals. The meter should indicate about 12.5 V and not less than 12.0 volts.

2.   With the key off, turn the headlights on and measure the battery post voltage. If the reading drops below 11.5 Volts,  the battery should be taken to an auto parts store and put on a load tester. A bad cell will sometimes set code 44 and cause drivability problems.

3.    With the headlights still ON, measure the voltage between each battery terminal and its battery post. A voltage difference greater than 0.1 V indicates that the terminal connection is corroded - remove the terminal from the post, clean both, grease them with petroleum jelly, and reinstall the terminal(s). Re-test to verify that each terminal has a good connection.

3.    Start the engine - the meter should read 13.8 - 14.5 volts. If the voltage is below 13.8V, the battery is not charging.

    Measure the voltage at the back of the alternator output (the large wire terminal)

4.    Turn the engine off, set the voltmeter to measure AC volts, and take a reading at the battery terminals. Now start the engine and measure the voltage at the alternator output - it should be almost identical to the voltage measured at the battery with the engine off. If the readings differ by more than 1 volt, there is a problem with the alternator diodes.

This page would not have been possible without the help of Hank LaViers,
who graciously loaned me his extensive Mopar engine library 


Last Update: August 8, 2001