DTC P1594: CHARGING SYSTEM VOLTAGE TOO HIGH Dodge Durango I

Note. For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.

Note. Charging system voltage is monitored when ignition is on and engine is running. DTC may be stored in Powertrain Control Module (PCM) if PCM attempts to regulate generator field with no detected field problems but voltage output does not decrease. Possible causes are: defective battery temperature sensor, defective generator, defective PCM, or defective connectors or wiring.

1. Turn ignition on with engine off. Using scan tool, actuate generator field driver. Using 12-volt test light, check for voltage at terminal No. 2 (Dark Green wire) on 2-wire connector at rear of generator. If test light flashes on and off, go to next step. If test light does not flash on and off, go to step 5 .
2. Using scan tool, stop actuation of generator field driver. Ensure ignition is on with engine off. Using scan tool, read target charging voltage. If target charging voltage is more than zero volts, go to next step. If target charging voltage is zero volts, go to step 4 .
3. Start engine and manually set engine speed to 1600 RPM. Using scan tool, read target charging voltage and battery voltage. Compare the 2 readings for 5 minutes. If voltage difference is not more than one volt, allow engine to return to idle. Shut engine off. Test is complete. If difference between the 2 readings is more than one volt, replace PCM. PCM is located at passenger's side front corner of engine compartment on inner fender panel. Perform «TEST VER-3»(ref-9482-S32123480852000102700000) .
4. Shut engine off. Using scan tool in INPUTS/OUTPUTS mode, read temperature of battery temperature sensor. Battery temperature sensor is located on battery tray, below battery and contains a 2-pin connector with Black/Light Blue and Pink/Yellow wires. Using thermometer, measure underhood temperature near battery tray. If underhood temperature is within 10 degrees of temperature of battery temperature sensor, replace PCM. PCM is located at passenger's side front corner of engine compartment on inner fender panel. Perform «TEST VER-3»(ref-9482-S32123480852000102700000) . If underhood temperature is not within 10 degrees of temperature of battery temperature sensor, replace battery temperature sensor. Perform «TEST VER-3»(ref-9482-S32123480852000102700000) .
5. Turn ignition off. Disconnect PCM connectors. PCM is located at passenger's side front corner of engine compartment on inner fender panel. Disconnect 2-wire connector at rear of generator. Using ohmmeter, check resistance between ground and terminal No. 10 (Dark Green wire) on PCM connector C2. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground on Dark Green wire between generator and PCM. Perform «TEST VER-3»(ref-9482-S32123480852000102700000) .
6. Ensure 2-wire connector at rear of generator is still disconnected. Using ohmmeter, check resistance between ground and generator field driver terminal in the generator. This is the terminal on rear of generator that Dark Green wire in the round 2-wire connector fits on. If resistance is 5 ohms or more, replace PCM. Perform «TEST VER-3»(ref-9482-S32123480852000102700000) . If resistance is less than 5 ohms, short exists in the generator. Repair or replace generator as necessary. Perform «TEST VER-3»(ref-9482-S32123480852000102700000) .