Charging System - Generators & Regulators Dodge Cab & Chassis R2500

MODEL IDENTIFICATION

Vehicle body codes are used throughout self-diagnostic tests. See BODY CODE DESIGNATION table for model identification.

BODY CODE DESIGNATION

DESCRIPTION

Chrysler Corp. light trucks use a Denso generator. The generator consists of a rotor, stator, rectifiers, front and rear covers and drive pulley. Generator is serviced as a complete unit only. Voltage regulation is controlled by the Powertrain Control Module (PCM). Electronic Voltage Regulator (EVR) is not a separate component, but a circuit located within the PCM. If EVR circuit is defective, PCM must be replaced.

GENERATOR APPLICATION

OPERATION

The amount of amperage produced by the generator is controlled by Electronic Voltage Regulator (EVR) circuitry within the PCM. EVR circuity is connected in series with the generator field driver terminal and ground. A Battery Temperature Sensor (BTS), located in battery tray, is used to sense battery temperature. Sensed battery temperature and data from monitored line voltage is used by PCM to adjust battery charging rate. This is accomplished by cycling the ground path to control the strength of generator rotor magnetic field. PCM then compensates and regulates generator amperage output accordingly. The PCM monitors critical input to control fuel injection, ignition, emission and other engine management functions. The PCM is also programmed to monitor charging system related circuits

1. Battery feed to PCM.
2. Generator field control.
3. Battery charging voltage (high & low).

If a problem is sensed in a monitored circuit, a Diagnostic Trouble Code (DTC) will be stored in PCM memory and Malfunction Indicator Light (MIL) will illuminate, provided specific criteria have been met. DTCs can be read using Chrysler's Diagnostic Readout Box (DRB-III), or a generic scan tool.

Note. DTC is erased from memory if failure does not reoccur after 40 engine warm-up cycles.

Certain DTCs cause MIL to illuminate and PCM to enter limp-in mode. In limp-in mode, PCM attempts to compensate for particular component failure by substituting information from other sources. This allows vehicle operation until proper repairs are made.

BELT TENSION

BELT TENSION

INITIAL CHECKS

Before proceeding with charging system diagnosis, ensure following conditions are met

1. Battery is fully charged and in good condition.
2. Battery cables are in good condition with connections clean and secure.
3. Generator belt is in good condition and properly tightened.
4. Generator and PCM wiring harness connections are clean and tight.
5. Engine ground strap is in place.

UNSTEADY OR LOW CHARGING

Check for loose generator belt, charging resistance too high, loose generator ground wire, corroded battery terminals or faulty generator.

OVERCHARGING

Check for grounded generator field wiring or faulty generator.

NOISY GENERATOR

Check for worn or frayed drive belt, loose generator mounting, or faulty generator.

SELF-DIAGNOSTIC SYSTEM

If a problem is sensed in a monitored circuit, a Diagnostic Trouble Code (DTC) will be stored in PCM and MIL will illuminate, provided specific criteria are met. PCM will then enter limp-in mode, substituting information from other sources to compensate for component failure. Vehicle is operational in limp-in mode, but driveability may not be optimal.

A specific DTC results from a particular system failure. DTC only indicates problem circuit. It does not identify specific component failure in the circuit.

If problem is repaired or ceases to exist, PCM automatically clears DTC after 40 engine warm-up cycles. DTCs can also be cleared using scan tool. See CLEARING DTCS .

PRECAUTIONS

Before proceeding with diagnosis, observe following precautions

1. Ensure battery is fully charged.
2. Probe PCM connector from pin side. DO NOT backprobe PCM connector or probe wires through insulation.
3. DO NOT cause short circuits when performing electrical tests. This will set additional DTCs, making diagnosis of original problem more difficult.
4. DO NOT use a test light in place of a voltmeter.
5. Always begin repair with lowest DTC number (MIL) or first DTC displayed (scan tool).
6. Always perform verification (VER) test after repairs are made.
7. Always disconnect scan tool after use.
8. Always disconnect scan tool before charging battery.

ON-BOARD DIAGNOSTICS

Note. PCM cannot diagnose every charging system problem. If fault still exists after performing self-diagnostic procedures, proceed to ON-VEHICLE TESTING .

RETRIEVING DTCS

Note. Self-diagnostic tests are written specifically for Chrysler's Diagnostic Readout Box (DRB-III) scan tool. A generic scan tool may also be used for system diagnostics, but may have limited diagnostic capability.

1. Ensure battery is fully charged. Connect scan tool to Data Link Connector (DLC). DLC is located below instrument panel, near steering column.
2. Using scan tool manufacturer's instructions, retrieve and record DTCs displayed on scan tool and proceed to «SELF-DIAGNOSTIC TESTS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__self-diagnostic-tests) . Once repairs are made, clear DTCs from PCM memory. See «CLEARING DTCS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__clearing-dtcs) .

CLEARING DTCS

PCM automatically clears DTCs from PCM memory after 40 engine warm-up cycles. DTCs can also be cleared using scan tool by following scan tool manufacturer's instructions.

Blank Message Screen

Check for loose cable connections or bad cable. If cable connections and cable are okay, check voltage at DLC terminal No. 16 (Pink wire). Voltage should be at least 11 volts. If voltage is not as specified, check wiring circuit and necessary fuses.

NO RESPONSE Message

See TEST NS-6A in appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

Note. For more information on scan tool and PCM diagnostics, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

SELF-DIAGNOSTIC TESTS

Note. When using diagnostic tests, DO NOT skip any steps in chart, or incorrect diagnosis may result. Ensure battery is fully charged.

DTC TEST: CHECKING SYSTEM FOR DIAGNOSTIC TROUBLE CODES

Note. For connector terminal identification, see CONNECTOR IDENTIFICATION in appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

1. Attempt to start engine. If necessary, crank engine for up to 10 seconds. Read and record DTCs. See «RETRIEVING DTCS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__retrieving-dtcs) under SELF-DIAGNOSTIC SYSTEM. If scan tool screen is blank or displays NO RESPONSE, see «SCAN TOOL PROBLEMS & ERROR MESSAGES»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) under SELF-DIAGNOSTIC SYSTEM.
2. If DTCs are displayed, see «SCAN TOOL DTC MESSAGES»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) table. Only DTCs relating to charging system are listed. For all other DTCs, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If no DTCs are displayed, go to «TEST CH-1A: CHARGING SYSTEM NO CODE TEST»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) .

SCAN TOOL DTC MESSAGES

DTC P0562: CHARGING SYSTEM VOLTAGE TOO LOW

Note. DTC P0562 is set when battery voltage at Engine Control Module (ECM) is less than 6 volts. Possible causes are charging system malfunction, open ECM ground circuits, open fused B+ circuits, battery cable resistance, low battery charge, high resistance in battery supply circuit to ECM and/or defective ECM.

1. If DTC P1682 is also set with P0562, repair DTC P1682 first before proceeding with DTC P0562. If DTC P1682 is not set, go to next step.
2. Inspect condition of battery cables. Ensure battery cables do not have high resistance. Repair or replace as needed. Perform «TEST VER-2A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-2a-road-test-verification) .
3. Ensure battery is fully charged. Charge as needed. Turn ignition off. Disconnect Engine Control Module (ECM) harness connector. ECM is attached to left side of engine behind fuel filter. Measure voltage between ground and terminals No. 48 and 50 on ECM harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to step 6 .
4. Inspect starter current draw. See appropriate STARTERS article. If starter current draw is within specification, go to next step. If starter current draw is not within specification or battery voltage is low, repair as needed. Perform «TEST VER-2A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-2a-road-test-verification) .
5. With ECM harness connector disconnected, measure voltage between terminal No. 48 and terminals No. 30 and 49 (ground circuits) on ECM harness connector. If battery voltage is present, replace ECM. Perform «TEST VER-2A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-2a-road-test-verification) . If battery voltage is not present, inspect and repair ground circuits as needed.
6. Inspect starter current draw. See appropriate STARTERS article. If starter current draw is within specification, go to next step. If starter current draw is not within specification or battery voltage is low, repair as needed. Perform «TEST VER-2A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-2a-road-test-verification) .
7. Turn ignition off. Remove fuse No. 3 from Power Distribution Center (PDC). Disconnect Engine Control Module (ECM) harness connector. ECM is attached to left side of engine behind fuel filter. Measure resistance between fuse No. 3 and terminals No. 48 and 50 on ECM harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair Red/White wire between PDC and ECM. Perform «TEST VER-2A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-2a-road-test-verification) .
8. With fuse remove from PDC, measure voltage between ground and fuse No. 3 socket. If battery voltage is present, replace ECM. If battery voltage is not present, repair circuit between battery and fuse No. 3 socket. Perform «TEST VER-2A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-2a-road-test-verification) .

DTC P0563: CHARGING SYSTEM VOLTAGE TOO HIGH

Note. DTC P0563 is set when battery supply voltage to Engine Control Module (ECM) is greater than 17 volts. Possible causes are charging system malfunction of open ground circuits at ECM.

1. Start engine. Backprobe ECM harness connector. ECM is attached to left side of engine behind fuel filter. Measure voltage between ground and terminals No. 48 and 50 on ECM harness connector. If voltage is less than 17 volts, go to next step. If voltage is 17 volts or greater, go to «TEST CH-1A: CHARGING SYSTEM NO CODE TEST»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) .
2. If DTC P1594 is also set with P0563, repair DTC P1594 first before proceeding with DTC P0563. If DTC P1594 is not set, go to next step.
3. Ensure ignition is off. Backprobe ECM harness connector. Measure voltage between ground and terminals No. 48 and 50 on ECM harness connector. If voltage is less than 17 volts, go to next step. If voltage is 17 volts or greater, inspect battery installation. Correct as necessary. Perform «TEST VER-2A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-2a-road-test-verification) .
4. Disconnect Engine Control Module (ECM) harness connector. Measure voltage between terminal No. 48 and terminals No. 30 and 49 (ground circuits) on ECM harness connector. If battery voltage is present, test is complete. If battery voltage is not present, inspect and repair ground circuits as needed. Perform «TEST VER-2A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-2a-road-test-verification) .

DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY

Note. DTC is set when PCM attempts to regulate generator field with no result during monitoring. Possible causes are generator field resistance greater than 5 ohms, open generator field driver circuit, generator field driver circuit shorted to ground, defective generator or PCM.

1. Record all DTC's and clear codes. Check all charging system related connectors for loose, corroded or damaged terminals. Repair as necessary. Using scan tool, actuate generator field driver circuit. Using a voltmeter, backprobe generator field connector generator field driver circuit. If voltage shifts from low to high, go to next step. If voltage does not shift from low to high, go to step 4 . NOTE: To identify field terminals, measure voltage between ground and each field terminal with engine running. Positive field terminal voltage should be 12.5-14.5 volts. Negative field terminal voltage should be 3-8 volts less than battery voltage.
2. Turn ignition on. Using scan tool, actuate generator field driver circuit. Using external voltmeter, measure voltage between ground and generator field source terminal (positive terminal) on 2-wire connector on rear of generator. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open in generator field source circuit between generator and PCM. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
3. Wiggle wiring harness from generator to PCM. Using scan tool, read DTCs with actuator test still running. If generator field driver circuit DTC sets, repair wiring harness as necessary where wiggling caused problem to appear. If DTC does not set, fault is currently not present. Test is complete. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) . NOTE: To identify field terminals, measure voltage between ground and each field terminal with engine running. Positive field terminal voltage should be 12.5-14.5 volts. Negative field terminal voltage should be 3-8 volts less than battery voltage.
4. Turn ignition on. Using scan tool, actuate generator field driver circuit. Using external voltmeter, measure voltage between ground and generator field source terminal (positive terminal) on 2-wire connector on rear of generator. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open in generator field source circuit between generator and PCM. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
5. Turn ignition off. Disconnect PCM harness connector. Disconnect field harness connector on rear of generator. Disconnect battery connections. Using an ohmmeter, measure resistance between generator field terminals on generator. If resistance is 5 ohms or more, repair or replace generator. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) . If resistance is less than 5 ohms, go to next step.
6. Using an ohmmeter, check resistance of generator field driver circuit between generator field harness connector and PCM harness connector. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If resistance is 5 ohms or more, repair open generator field driver circuit. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) . If resistance is less than 5 ohms, go to next step.
7. With generator field connector disconnected, measure resistance from either generator field terminal (on back of generator) to ground. If resistance is less than 5 ohms, repair or replace shorted generator. If resistance is 5 ohms or more, replace PCM. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .

DTC P1492: BATTERY TEMP SENSOR VOLTAGE TOO HIGH

Note. Battery Temperature Sensor (BTS) is also known as Ambient Temperature Sensor (ATS).

1. Ensure ignition is on. Read Battery Temperature Sensor (BTS) voltage using scan tool. If BTS voltage is greater than 4.5 volts, go to next step. If BTS voltage is 4.5 volts or less, go to step 6 .
2. Disconnect BTS connector. BTS is located in bottom of battery tray. Connect jumper wire between ground and terminal No. 2 (Pink/Yellow wire) on BTS harness connector. Turn ignition on. Using scan tool, read BTS voltage. If BTS voltage is less than one volt, go to next step. repair open BTS ground circuit. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If BTS voltage is one volt or more, go to next step.
3. Turn ignition off. Move jumper wire between BTS harness connector terminals. Turn ignition on. Using scan tool, read BTS voltage. If BTS voltage is less than one volt, replace BTS. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If BTS voltage is one volt or more, remove jumper wire and go to next step.
4. Measure voltage between ground and terminal No. 2 (Pink/Yellow wire) on BTS harness connector. If voltage is greater than 6 volts, repaie BTS sensor signal circuit for short to voltage. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If voltage is 6 volts or less, go to next step.
5. Turn ignition off. Disconnect Powertrain Control Module (PCM) connector. Using an ohmmeter, check resistance of BTS signal circuit between ground and terminal No. 2 on BTS harness connector. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__removal-installation) . If resistance is less than 5 ohms, replace PCM. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If resistance is 5 ohms or greater, repair open BTS signal circuit. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) .
6. While observing scan tool BTS voltage, wiggle wiring harness for BTS sensor. If voltage changes, repair wiring harness as necessary where wiggling caused problem to appear. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If voltage does not change, inspect all related wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, DTC may have been set by intermittent condition.

DTC P1493: BATTERY TEMP SENSOR VOLTAGE TOO LOW

Note. Battery Temperature Sensor (BTS) is also known as Ambient Temperature Sensor (ATS).

1. Ensure ignition is on. Using scan tool, read Battery Temperature Sensor (BTS) voltage. If BTS voltage is less than .5 volts, go to next step. If BTS voltage is .5 volts or greater, go to step 5 .
2. Turn ignition off. Disconnect BTS connector. BTS is located in bottom of battery tray. Turn ignition on. Read Battery Temperature Sensor (BTS) voltage. If BTS voltage is greater than 4 volts, replace BTS. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If BTS voltage is 4 volts or less, go to next step.
3. Ensure ignition is off and BTS is disconnected. Disconnect Powertrain Control Module (PCM) connector. Using an ohmmeter, measure resistance of BTS signal circuit between ground and terminal No. 2 on BTS harness connector. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__removal-installation) . If resistance is less than 5 ohms, repair BTS signal circuit for short to ground. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If resistance is 5 ohms or greater, go to next step.
4. Measure resistance between BTS harness connector terminals. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__removal-installation) . If resistance is less than 5 ohms, repair BTS signal circuit shorted to sensor gound circuit. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If resistance is 5 ohms or greater, replace PCM. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) .
5. While observing scan tool BTS voltage, wiggle wiring harness for BTS sensor. If voltage changes, repair wiring harness as necessary where wiggling caused problem to appear. Perform «TEST VER-5A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-5a-road-test-verification) . If voltage does not change, inspect all related wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, inspect all related wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, DTC may have been set by intermittent condition.

DTC P1594: CHARGING SYSTEM VOLTAGE TOO HIGH

Note. DTC is set when monitored battery voltage is one volt below charging system upper limit threshold for 25 seconds. PCM turns off field driver and monitors battery voltage. If voltage remains high, DTC P1594 is set. Possible causes are generator field driver circuit shorted to ground, shorted generator or Powertrain Control Module (battery temperature and/or charging voltage).

1. Ensure battery is fully charged, and generator belt tension and condition are okay. Using scan tool, actuate generator field driver. Using a voltmeter, backprobe generator field connector. Measure voltage between ground and terminal No. 1 (Dark Green or Dark Green/White wire) on generator field connector. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If voltage shifts from low to high, go to next step. If voltage does not shift from low to high, go to step 6 .
2. Using scan tool, stop generator field driver actuation. Start engine. Using scan tool, read target charging voltage. If target charging voltage is more than 13 volts, go to step 4 . If target charging voltage is 13 volts or less, go to next step.
3. Measure underhood temperature near battery using scan tool temperature probe. Using scan tool, read battery temperature sensor temperature. If scan tool display is within 10 degrees of actual underhood temperature, go to next step. If scan tool display is not within 10 degrees of actual underhood temperature, replace BTS. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
4. Start engine. Manually set engine speed to 1600 RPM. Using scan tool, read and compare voltage and target charging voltage. Observe voltage for up to 5 minutes (if necessary) for a one volt difference between voltage and target charging voltage. If difference between voltage and target charging voltage is one volt or less, go to «TEST CH-1A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If difference between voltage and target charging voltage is more than one volt, replace Powertrain Control Module (PCM). Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
5. Turn ignition off. Disconnect PCM harness connector. Disconnect field harness connector on rear of generator. Using an ohmmeter, measure resistance of generator field driver circuit between PCM connector and ground. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground on generator field driver circuit. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
6. With generator field connector disconnected, measure resistance from either generator field terminal (on back of generator) to ground. If resistance is less than 5 ohms, repair or replace shorted generator. If resistance is 5 ohms or more, replace PCM. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .

DTC P1682: CHARGING SYSTEM VOLTAGE TOO LOW

Note. DTC is set when monitored battery voltage is one volt below charging system lower limit threshold for 25 seconds. PCM turns off field driver and monitors battery voltage. If voltage remains low, DTC P1682 is set. Possible causes are open high resistance in battery supply circuit between generator and battery, open field driver circuit, high resistance in ground circuit, defective generator or defective battery temperature sensor.

1. Ensure battery is fully charged. Start engine. Using scan tool, read voltage goal. If voltage goal is more than 15.1 volts, go to next step. If voltage goal is 15.1 volts or less, go to step 4 .
2. Ensure engine is at normal operating temperature. Using scan tool, read Battery Temperature Sensor (BTS) temperature. Measure underhood temperature. If BTS temperature is within 10 degrees of actual underhood temperature, go to step 4 . If BTS temperature is not within 10 degrees of actual underhood temperature, go to next step.
3. Turn ignition off. Disconnect BTS harness connector. BTS is mounted in bottom of battery tray. Connect jumper wire across BTS harness connector terminals. Turn ignition on. Using scan tool, read BTS voltage. If voltage is zero, replace BTS. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) . If voltage is present, replace PCM. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
4. Start engine and manually set engine speed to 1600 RPM. Using scan tool, read and compare target voltage and charging voltage. If difference between target voltage and charging voltage is more than one volt, go to next step. If difference between target voltage and charging voltage is one volt or less, go to step 12 . NOTE: Before starting engine, ensure all test equipment wires are clear of moving engine parts.
5. Connect an external voltmeter between generator B+ terminal and battery positive terminal. Start engine. If voltage is .4 volt or less, go to next step. If voltage is more than .4 volt, repair B+ circuit for high resistance between generator and battery. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
6. Turn ignition off. Connect an external voltmeter between generator case and battery negative terminal. Start engine. If voltage is .1 volt or less, go to next step. If voltage is more than .1 volt, repair generator ground for high resistance between generator case and battery negative terminal. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
7. With ignition on and engine not running, acutate generator field. Using voltmeter, measure voltage between ground and each generator field terminal. If voltage on both terminals is less than 3 volts, go to next step. If voltage for either terminal is 3 volts or greater, charging system is currently functioning correctly. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
8. Turn ignition off. Disconnect Powertrain Control Module (PCM) harness connector. Using ohmmeter, measure resistance between ground and generator field driver terminal on PCM harness connector. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If resistance is less than 5 ohms, repair field driver circuit for short to ground. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) . If resistance is 5 ohms or greater, go to next step.
9. Disconnect generator field connector. Measure resistance of generator field driver circuit between PCM and generator field harness connector. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open field driver circuit. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
10. Using ohmmeter, measure resistance between ground and generator field source terminal on PCM harness connector. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If resistance is less than 5 ohms, repair field source circuit for short to ground. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) . If resistance is 5 ohms or greater, go to next step.
11. Disconnect generator field connector. Measure resistance of generator field source circuit between PCM and generator field harness connector. See «WIRING DIAGRAMS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) . If resistance is less than 5 ohms, replace PCM. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) . If resistance is 5 ohms or greater, repair open field source circuit. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) . NOTE: Before starting engine, ensure all test equipment wires are clear of moving engine parts.
12. Connect an external voltmeter between generator B+ terminal and battery positive terminal. Start engine. If voltage is .4 volt or less, go to next step. If voltage is more than .4 volt, repair B+ circuit for high resistance between generator and battery. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .
13. Turn ignition off. Connect an external voltmeter between generator case and battery negative terminal. Start engine. If voltage is .1 volt or less, test is complete. If voltage is more than .1 volt, repair generator ground for high resistance between generator case and battery negative terminal. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification) .

Scheme 1

Scheme 2

1. Verify battery condition. Charge or replace battery as necessary. Inspect generator belt tension and condition. Replace generator belt as necessary. Start engine. Turn on all accessories. Set engine speed to 2000 RPM for 30 seconds, then return to idle. Read Diagnostic Trouble Codes (DTCs). See «SCAN TOOL DTC MESSAGES»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) table. If any charging system DTCs are set, perform appropriate test. If no charging system DTCs are set, go to next step.
2. With ignition on and engine off, read and record battery voltage using scan tool. Using voltmeter, measure and record voltage between battery posts. If voltage difference is less than one volt, test is complete. If voltage difference is one volt or greater, go to next step.
3. Turn ignition on with engine off. Using scan tool, actuate generator field. Using voltmeter, backprobe generator field terminals on back of generator. Measure voltage between ground and each field terminal. (Scheme 1)or (Scheme 2). Voltage should cycle from zero volts to battery voltage every 1.4 seconds at both terminals. While observing scan tool, wiggle field terminal wiring harness back to Powertrain Control Module (PCM). If any interruption of voltage cycling occurred, repair wiring harness where wiggling caused failure. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification). If wiggling did not interrupt voltage cycling, go to next step.
4. Using an external voltmeter, check voltage between generator B+ terminal located on rear of generator and battery positive terminal. (Scheme 1)or (Scheme 2). Ensure voltmeter wires are clear of moving engine parts. Start engine and observe voltmeter. If voltage is.4 volt or less, go to next step. If voltage is more than.4 volt, repair high resistance between generator B+ terminal and battery positive terminal. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification).
5. Using scan tool, read DTCs. If any charging system DTCs are set, see «SCAN TOOL DTC MESSAGES»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) table and perform appropriate test. If no charging system trouble codes are set, go to next step.
6. Turn ignition off. Using an external voltmeter, check voltage between generator case and battery negative terminal. Start engine. If voltage is greater than.1 volt, repair high resistance between generator battery negative terminal and battery negative terminal. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification). If voltage is.1 volt or less, go to next step.
7. With ignition on and engine off, read and record battery voltage using scan tool. Turn ignition off. Disconnect PCM connector. Turn ignition on. Using voltmeter, measure voltage between ground and terminal No. 22 on PCM connector C1. If voltage is within one volt of scan tool voltage, repair high resistance between PCM connector terminal No. 22 and battery positive terminal. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification). If voltage is not within one volt of scan tool voltage, replace PCM. Perform «TEST VER-3A»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__test-ver-3a-charging-verification).

TEST VER-2A: ROAD TEST VERIFICATION

1. If PCM has been replaced, go to next step. If ECM has been replaced or battery has been disconnected on diesel powered vehicles, go to step 3 . If neither module has been replaced, go to step 4 .
2. Connect scan tool to Data Link Connector (DLC). DLC is located below driver's side of instrument panel. Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from ABS and SRS modules.
3. Programming of Accelerator Pedal Position Sensor (APPS) is necessary if ECM has been replaced or battery has been disconnected on diesel powered vehicles. Ensure all components are connected. Turn ignition on. Slowly depress accelerator pedal to floor, then slowly release. APPS is now programmed. Go to next step.
4. Inspect vehicle to ensure all engine components are connected. Reassemble and reconnect components as necessary.
5. Check if initial symptom still exists. If initial or another symptom exists, repair is not complete. Check for Technical Service Bulletins (TSBs) that apply to symptom.
6. If any DTCs have not been diagnosed, go to appropriate test and finish diagnosing remaining DTCs as necessary. If all DTCs have been diagnosed, go to next step.
7. Using scan tool, erase DTCs from PCM. Using scan tool, reset all values in adaptive memory. Disconnect scan tool. If no other DTCs remain, repair is now complete.

TEST VER-3A: CHARGING VERIFICATION

1. If PCM has been replaced, go to next step. If ECM has been replaced or battery has been disconnected on diesel powered vehicles, go to step 3 . If neither module has been replaced, go to step 4 .
2. Connect scan tool to Data Link Connector (DLC). DLC is located below driver's side of instrument panel. Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from ABS and SRS modules.
3. Programming of Accelerator Pedal Position Sensor (APPS) is necessary if ECM has been replaced or battery has been disconnected on diesel powered vehicles. Ensure all components are connected. Turn ignition on. Slowly depress accelerator pedal to floor, then slowly release. APPS is now programmed. Go to next step.
4. Inspect vehicle to ensure all engine components are connected. Reassemble and reconnect components as necessary.
5. To ensure no charging system problem exists, start engine. Perform «OUTPUT VOLTAGE TEST»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__voltage-output-test) under ON-VEHICLE TESTING. Increase engine speed to 2000 RPM for at least 30 seconds. Allow engine to idle. Turn engine off.
6. Using scan tool, check for stored DTCs. If repaired DTC has reset, repair is not complete. Check for related Technical Service Bulletins (TSBs) and return to DTC TEST, if necessary. If another DTC exists, go to appropriate DTC test and follow specified procedure. If no other DTCs exist, repair is now complete.

TEST VER-5A: ROAD TEST VERIFICATION

1. If PCM has been replaced, go to next step. If ECM has been replaced or battery has been disconnected on diesel powered vehicles, go to step 3 . If neither module has been replaced, go to step 4 .
2. Connect scan tool to Data Link Connector (DLC). DLC is located below driver's side of instrument panel. Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from ABS and SRS modules.
3. Programming of Accelerator Pedal Position Sensor (APPS) is necessary if ECM has been replaced or battery has been disconnected on diesel powered vehicles. Ensure all components are connected. Turn ignition on. Slowly depress accelerator pedal to floor, then slowly release. APPS is now programmed. Go to next step.
4. Connect scan tool to Data Link Connector (DLC). DLC is located below driver's side of instrument panel. Using scan tool, enter correct VIN and mileage into PCM. Using scan tool manufacturer's instructions, clear DTCs from ABS and SRS modules.
5. Inspect vehicle to ensure all engine components are connected. Reassemble and reconnect components as necessary.
6. If any DTCs have not been diagnosed, go to appropriate test and finish diagnosing remaining DTCs as necessary. If all DTCs have been diagnosed, go to next step.
7. Connect scan tool to DLC connector. Ensure fuel tank is at least 25 percent full. Turn off all accessories.
8. Using scan tool OBDII monitor, verify DTC repair. See scan tool instructions. Allow PCM to run appropriate monitor(s) and increment a global good trip (drive cycle). Enabling conditions must be met before PCM will run OBDII monitor. Scan tool monitor pretest screen will display enabling conditions.
9. If repaired DTC has reset or was seen in OBDII monitor while on road test, repair is not complete. Check for any TSBs and return to appropriate test. Repair as needed.
10. If any other DTCs are set, repair as needed. If OBDII monitor is run and good trip counter is incremented and no new DTCs are set, repair is successful and complete. Erase DTCs. See «CLEARING DTCS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__clearing-dtcs) under SELF-DIAGNOSTIC SYSTEM.

ON-VEHICLE TESTING

VOLTAGE DROP TEST

Note. VOLTAGE DROP TEST determines amount of resistance in circuits between generator and battery.

Testing Positive Circuit

1. Ensure battery is in condition and is fully charged. Clean battery terminals (if necessary). Using external voltmeter, connect positive lead to generator B+ terminal stud (not the nut). Connect voltmeter negative lead to positive battery post. Connect tachometer to engine. Fully engage parking brake, and place gear selector in Neutral position. Start engine and run for 2 minutes to allow for warm-up.
2. Turn A/C system on, A/C-heater blower motor to high speed and headlights on high beam. Increase engine speed to 2400 RPM. Voltmeter reading should not be more than 0.6 volts.
3. If voltage drop is more than 0.6 volts, inspect, clean and tighten all connections between generator B+ terminal and positive battery post. Voltage drop test may be performed at each connection to locate connection with excessive resistance. If resistance tests are satisfactory, reduce engine speed, turn off all electrical loads and ignition switch.

Testing Negative Circuit

1. Using external voltmeter, connect negative lead of voltmeter to negative battery post and postive lead to groung terminal stud on back of generator case. Voltmeter reading should not be more than 0.3 volts.
2. If voltage drop is more than 0.3 volts, inspect, clean and tighten all connections between generator ground terminal and negative battery post. Voltage drop test may be performed at each connection to locate connection with excessive resistance. If resistance tests are satisfactory, reduce engine speed, turn off all electrical loads and ignition switch.

CURRENT OUTPUT TEST

Note. Perform VOLTAGE DROP TEST before continuing with this test. Perform test soon after starting engine, as charging amperage will drop quickly. A volt/amp tester equipped with both a battery load control (carbon pile rheostat) and an inductive type pick-up clamp is required to perform the following test.

1. Ensure battery is in good condition and is fully charged. Clean battery terminals (if necessary). Connect volt/amp tester leads to battery. Ensure carbon pile is in OFF position before connecting leads. Connect inductive pick-up clamp.
2. Connect tachometer to engine. Start engine and raise engine speed to 2500 RPM. Slowly adjust rheostat control (load) on volt/amp tester until highest amperage reading is obtained. DO NOT allow voltage to drop less than 12 volts.
3. Note reading on ammeter. Generator amperage reading should be greater than minimum amperage rating specification. See «GENERATOR APPLICATION»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators) table under DESCRIPTION. If amperage is not within minimum specification, go to next step.
4. Rotate load control knob to OFF position. Continue to hold engine speed at 2500 RPM. Output amperage should change to less than 20 amps, indicating EVR circuity is okay and charging system is functioning properly. It may take several minutes for amperage to change. If amperage does not significantly decrease, check battery. Using scan tool, check for any possible DTCs. See «SELF-DIAGNOSTIC SYSTEM»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__self-diagnostic-system) .

VOLTAGE OUTPUT TEST

1. Before performing this test, ensure battery is fully charged. Connect voltmeter leads across battery terminals. Record voltage with ignition switch and all electrical loads off. Fully engage parking brake, and place gear selector in Park position.
2. Start engine and operate at normal operating temperature. Record voltage with engine speed at 1500 RPM and no electrical loads. Voltage should not be greater than voltage recorded in step 1) by more than 2.5 volts. If voltage is not as specified, check if any DTCs are present. See «SELF-DIAGNOSTIC SYSTEM»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__self-diagnostic-system) .
3. Record voltage with engine speed at 2000 RPM, blower motor on high and headlights on high beam. Voltage should be more than 0.5 volt above battery voltage previously recorded in step 1) . If voltage is less than 0.5 volt above previously recorded battery voltage, check if any DTCs are present. See «SELF-DIAGNOSTIC SYSTEM»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__self-diagnostic-system) . If voltage tests are satisfactory, reduce engine speed, and turn off blower motor, headlights and ignition switch.

BATTERY TEMPERATURE SENSOR

Disconnect and remove Battery Temperature Sensor (BTS) for battery tray (driver's side tray on diesel equipped vehicle). Using external ohmmeter, measure resistance across component connector terminals. Resistance at room temperature should be 9000-11,000 ohms. Replace sensor as needed.

REMOVAL & INSTALLATION

1. Disconnect negative battery cable. Remove generator drive belt and generator mounting bolts. Remove pivot bolt, and position generator aside to access wire connectors.
2. Remove B+ terminal nut, field terminal nuts and ground/wire harness hold-down nuts. Remove wire connectors. Remove generator from vehicle. To install, reverse removal procedure. Tighten fasteners to specification. See «TORQUE SPECIFICATIONS»(/dodge/cab-chassis-r2500/1996-2002/remont/charging-system/#charging-system-generators-regulators__torque-specifications) .

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

Charging System Wiring Diagram (Dakota). Scheme 3

Charging System Wiring Diagram (Durango). Scheme 4

Charging System Wiring Diagram (Ram Pickup). Scheme 5

Charging System Wiring Diagram (Ram Van & Ram Wagon). Scheme 6

See also:
• BODY CODE DESIGNATION
• CLEARING DTCS
• INITIAL CHECKS
• ON-VEHICLE TESTING
• SELF-DIAGNOSTIC TESTS
• RETRIEVING DTCS
• TEST VER-2A
• TEST VER-3A
• TEST VER-5A
• WIRING DIAGRAMS
• OUTPUT VOLTAGE TEST
• VOLTAGE DROP TEST
• SELF-DIAGNOSTIC SYSTEM
• TORQUE SPECIFICATIONS