Charging System - Generators & Regulators: Diagnosis Ford Taurus IV facelift

TROUBLE SHOOTING

Note. See CHARGING SYSTEM TROUBLE SHOOTING in BASIC TROUBLE SHOOTING article in GENERAL INFORMATION.

BATTERY TEST WITH DIGITAL BATTERY ANALYZER

Connect digital battery analyzer to battery and follow on screen instructions. If battery test good, return to service. If battery does not test good, replace battery.

BATTERY DRAIN TEST

Note. Amperage draw will vary from vehicle to vehicle depending on equipment package. Compare to a comparable vehicle for reference. No production vehicle should have more than a 50 mA (0.050 amp) draw.

1. Ensure junction box/fuse panels are accessible without turning on interior and hood lights. Drive vehicle over 30 MPH for at least 5 minutes. Park vehicle and allow to sit with ignition off for at least 40 minutes to allow electronic modules to power down. Go to next step.
2. Connect a fused jumper wire between negative battery cable and negative battery post. Disconnect negative battery cable from negative battery post, without breaking the jumper wire connection to prevent modules from resetting. Go to next step. NOTE: It is very important that continuity is not broken between negative battery post and negative battery cable when disconnecting battery cable or connecting ammeter. If continuity is broken, go to step 1 .
3. Ensure ammeter is set to read milliamps with at least a 10 amp capability. Connect ammeter between negative battery cable and negative battery post. Remove fused jumper wire. Go to next step.
4. If excessive current draw is present (50 mA or more), pull fuses from battery/smart junction box one at a time and note any current drop when each fuse is removed. DO NOT reinstall fuses until test is complete. Go to next step.
5. Check wiring diagrams for any circuits that run from battery without passing through battery/smart junction box. Disconnect these circuits if current draw still exists. Repair appropriate circuits as necessary. See POWER DISTRIBUTION in appropriate SYSTEM WIRING DIAGRAMS article.

GENERATOR LOAD TEST

Ensure drive belt is in good condition. Replace belt as necessary. If belt is okay, connect charging system load tester in accordance with manufacturer's instructions. Start and run engine at 2000 RPM, and apply load until generator output levels off. Generator amperage should be at least 87 amps with engine at 2000 RPM. Go to next step. If output is not as specified, see SYMPTOM INDEX table under SYSTEM TESTS.

GENERATOR NO-LOAD TEST

Connect voltmeter positive lead to B+ terminal on generator and negative lead to ground. Start and run engine at 2000 RPM with no electrical load (all accessories off). Read voltmeter when voltage stabilizes. Voltage should be 13-15 volts. If voltage is not as specified, see SYMPTOM INDEX table under SYSTEM TESTS.

SELF-DIAGNOSTIC SYSTEM

Note. All diagnostic tests are written specifically for New Generation Star (NGS) tester. Most generic OBD-II compliant scan tools should be able to perform all test procedures.

DIAGNOSTIC FORMATS

QUICK TEST and SYSTEM TESTS are diagnostic formats used to test and service EEC-V system. QUICK TEST allows technician to identify concerns and retrieve Diagnostic Trouble Codes (DTC). SYSTEM TESTS are used to check circuits, sensors and actuators.

Before starting any SYSTEM TEST, follow all steps under QUICK TEST to determine appropriate system test to perform. If vehicle passes QUICK TEST and no driveability symptoms or intermittent faults exist, EEC-V system is okay.

DIAGNOSTIC TROUBLE CODES

During QUICK TEST, 3 types of Diagnostic Trouble Codes (DTCs) are retrieved and diagnosis must be performed in the following order: Key On Engine Off (KOEO), Key On Engine Running (KOER) and Continuous Memory DTCs. See QUICK TEST for self-test procedures. DTCs may be cleared from PCM memory after DTCs have been recorded or fault has been repaired. See CLEARING CODES . If fault is still present after clearing DTCs, fault will reset. If no DTCs are present, diagnose by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.

KOEO & KOER On-Demand Self-Test Codes

Record DTCs in order received. These DTCs indicate current faults in system and should be serviced in order of appearance. See DIAGNOSTIC TROUBLE CODE DEFINITIONS under QUICK TESTS to identify appropriate system test to perform.

QUICK TEST

Quick Test is divided into 3 specialized test procedures that are functional tests of EEC-V system. All self-tests are completely menu driven using the New Generation Star (NGS) scan tool. The following procedures must be followed in sequence to avoid misdiagnosis

1. «VISUAL CHECK»(ref-165592-S27455995312004083000000)
2. «VEHICLE PREPARATION & EQUIPMENT HOOKUP»(ref-165592-S21061339322004083000000)
3. «KOEO ON-DEMAND SELF-TEST»(ref-165592-S27160879902004083000000)
4. «KOER ON-DEMAND SELF-TEST»(ref-165592-S36453985932004083000000)
5. «CONTINUOUS MEMORY SELF-TEST»(ref-165592-S40763890032004083000000)

Complete QUICK TEST before performing any system tests. Record any DTCs retrieved. Service DTCs in the following order: KOEO DTCs, KOER DTCs, then Continuous Memory DTCs and service first DTC output. If servicing Continuous Memory DTCs, retrieve any available freeze frame data. See FREEZE FRAME DATA MODE under ADDITIONAL SYSTEM FUNCTIONS in appropriate SELF-DIAGNOSTICS article under ENGINE PERFORMANCE. Disregard any identical or related Continuous Memory DTCs if previously serviced. After each service or repair procedure has been completed, always repeat QUICK TEST procedures to ensure all EEC-V systems are working properly and DTCs are no longer present.

Performing Self-Test

To perform self-test, turn ignition switch to OFF position. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select KOEO ON-DEMAND SELF-TEST.
7. Turn ignition switch to ON position.
8. Follow operating instructions from scan tool menu.
9. Record DTCs and perform appropriate system test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-165592-S34113159422004083000000) . After KOEO on-demand self-test is complete, cycle ignition switch before performing other self-tests or driving vehicle.

BPP, PSP & TCS Test Procedures

This test ensures EEC-V system is able to detect a change of state in brakelight switch, TCS and PSP switches. During KOER on-demand self-test, the brake pedal must be applied and then released, TCS must be cycled, and steering wheel must be turned at least 1/4 of a revolution.

Retrieve any available freeze frame data prior to self-test. See FREEZE FRAME DATA MODE under ADDITIONAL SYSTEM FUNCTIONS in appropriate SELF-DIAGNOSTICS article under ENGINE PERFORMANCE. To perform self-test, turn ignition switch to OFF position. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select RETRIEVE/CLEAR CONTINUOUS DTCs.
7. Turn ignition switch to ON position.
8. Follow operating instructions from scan tool menu.
9. Record DTCs and perform appropriate system test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-165592-S34113159422004083000000) . After continuous memory self-test is complete, cycle ignition switch before performing other self-tests or driving vehicle.

Retrieve any available freeze frame data prior to self-test. See FREEZE FRAME DATA MODE under ADDITIONAL SYSTEM FUNCTIONS in appropriate SELF-DIAGNOSTICS article under ENGINE PERFORMANCE. To perform self-test, turn ignition switch to OFF position. Ensure test equipment is properly attached. Program scan tool using the following steps

1. Select VEHICLE & ENGINE SELECTION menu.
2. Select NEW VEHICLE, YEAR & MODEL.
3. Select DIAGNOSTIC DATA LINK.
4. Select POWERTRAIN CONTROL MODULE.
5. Select DIAGNOSTIC TEST MODE.
6. Select RETRIEVE/CLEAR CONTINUOUS DTCs.
7. Turn ignition switch to ON position.
8. Follow operating instructions from scan tool menu.
9. Record DTCs and perform appropriate system test. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-165592-S34113159422004083000000) . After continuous memory self-test is complete, cycle ignition switch before performing other self-tests or driving vehicle.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

POWERTRAIN CONTROL MODULE (PCM) DTC INDEX

TEST A: BATTERY IS DISCHARGED OR VOLTAGE IS LOW

1. Check Battery Condition Perform battery condition test to determine if the battery can hold a charge and is okay for use. See «BATTERY TEST WITH DIGITAL BATTERY ANALYZER»(ref-165592-S31685670992004083000000) under ON-VEHICLE TESTING. Did the battery pass the condition test? If yes, go to next step. If no, install a new battery. Test the system for normal operation.
2. Check Generator Output Perform generator load and no-load tests. See «GENERATOR LOAD TEST»(ref-165592-S04350352372004083000000) and «GENERATOR NO-LOAD TEST»(ref-165592-S22345607652004083000000) under ON-VEHICLE TESTING. Did the generator pass the component tests? If yes, go to next step. If no, install a new generator. See «GENERATOR»(ref-165592-S03554965692004083000000) under REMOVAL & INSTALLATION. Test the system for normal operation.
3. Check For Current Drains Perform «BATTERY DRAIN TEST»(ref-165592-S26998515372004083000000) under ON-VEHICLE TESTING. Are any circuits causing excessive current drains? If yes, repair as necessary. Test system for normal operation. If no, go to next step.
4. Check Vehicle Grounds Start engine. Measure the voltage drop between the generator housing and the negative battery terminal. Is the voltage drop less than 0.1 volt? If yes, go to next step. If no, check the engine ground, generator ground and the battery ground for corrosion. Repair as necessary. Test the system for normal operation.
5. Check Voltage Drop In B+ Circuit (Yellow/White Wire) Measure the voltage drop between the generator B+ terminal (Yellow/White wire) and the positive battery terminal. Is the voltage drop less than 0.1 volt? If yes, verify if the customer left any component(s) on or if there is an intermittent excessive battery draw. Test the system for normal operation. If no, check for any corrosion in the positive battery cable and/or connections. Repair as necessary. Test the system for normal operation.

TEST B: WARNING INDICATOR ON WITH ENGINE RUNNING, SYSTEM NOT CHARGING

1. Check For Fault Codes In PCM Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If DTC P0622 was retrieved, follow the NO direction. Are any PCM DTCs recorded? If no, go to next step. If yes, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
2. Check Generator B+ Circuit (Yellow/White Wire) For Voltage Turn ignition off. Measure the voltage between the generator B+ terminal (Yellow/White wire) and ground. Is the voltage approximately equal to battery positive voltage? If yes, go to next step. If no, repair the circuit. Test the system for normal operation.
3. Check Generator Integrity Disconnect generator 3-pin connector. Start engine. If the generator communication lines are disconnected (DTC P0622 may set), the generator will self-excite if the engine is operated at greater than 2000 engine RPM for a momentary period of time. It will then operate in a default mode of approximately 13.5 volts until the engine is turned off. With the engine running at approximately 2000 RPM, measure the battery voltage. Is the battery voltage approximately 13.5 volts? If yes, go to next step. If no, install a new generator. See «GENERATOR»(ref-165592-S03554965692004083000000) under REMOVAL & INSTALLATION. Test the system for normal operation.
4. Check GEN COM Circuit (Light Blue/Red Wire) For An Open Or Short To Ground Turn ignition off. Disconnect PCM connector C175. Measure the resistance between the generator connector terminal No. 2 (Light Blue/Red wire) and the PCM connector C175 terminal No. 45, and between the generator connector terminal No. 2 (Light Blue/Red wire) and ground. (Scheme 1)or (Scheme 2) and (Scheme 3). Is the resistance less than 5 ohms between the generator and the PCM and greater than 10,000 ohms between the generator and ground? If yes, go to next step. If no, repair the circuit. Test the system for normal operation.
5. Check GEN MON Circuit (Gray/Yellow wire) For An Open Or Short To Ground Measure the resistance between the generator connector terminal No. 1 (Gray/Yellow wire) and the PCM connector C175 terminal No. 20, and between the generator connector terminal No. 1 (Gray/Yellow wire) and ground. (Scheme 1)or (Scheme 2) and (Scheme 3). Is the resistance less than 5 ohms between the generator and the PCM and greater than 10,000 ohms between the generator and ground? If yes, go to next step. If no, repair the circuit. Test the system for normal operation.
6. Check For Correct PCM Operation Disconnect PCM connector. Check for corrosion and pushed-out pins. Connect PCM connector and make sure it seats correctly. Operate the system and verify the concern is still present. Is the concern still present? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Test the system for normal operation. If no, the system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. Clear the DTCs. Repeat the self-test. Test the system for normal operation.

Scheme 1

Scheme 2

Scheme 3

TEST C: SYSTEM OVERCHARGES (MORE THAN 15 VOLTS)

1. Check For Fault Codes In PCM Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If DTC P0622 was retrieved, follow the NO direction. Are any PCM DTCs recorded? If no, go to next step. If yes, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
2. Check Battery Voltage Turn ignition off. Disconnect NGS tester. Start engine. With engine running and all accessories turned off, measure the voltage at battery while varying engine RPM. Is the voltage greater than 15.5 volts? If yes, go to next step. If no, go to step 4.
3. Check For Voltage Drop In "A" Circuit (Orange/Yellow wire) Turn ignition off. Disconnect generator 3-pin connector. Measure voltage between ground and generator harness connector terminal No. 3 (Orange/Yellow wire). (Scheme 1)or (Scheme 2). Is the voltage within 0.5 volt from battery voltage? If yes, reconnect generator 3-pin connector and go to next step. If no, repair Orange/Yellow wire. See «WIRING DIAGRAMS»(ref-165592-S24270798232004083000000). After repair, clear DTCs and test system for normal operation.
4. Check Generator PIDs Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Start engine. Enter MONITOR PCM PIDs diagnostic mode on the diagnostic tool. With the engine running, monitor the generator output fault PID in the PCM. Does the PID read YES? If yes, go to next step. If no, go to step 6.
5. Check Generator Integrity Turn ignition off. Disconnect generator 3-pin connector. Start engine. If the generator communication lines are disconnected (DTC P0622 may be set), the generator will self-excite if it is operated at greater than 2000 engine RPM for a momentary period of time. It will then operate in a default mode of approximately 13.5 volts until the engine is turned off. With the engine running at approximately 2000 RPM, measure the battery voltage. Is the battery voltage approximately 13.5 volts? If yes, go to next step. If no, install a new generator. See «GENERATOR»(ref-165592-S03554965692004083000000) under REMOVAL & INSTALLATION. Test the system for normal operation.
6. Check For Correct PCM Operation Disconnect PCM connector. Check for corrosion and pushed-out pins. Connect PCM connector and make sure it seats correctly. Operate the system and verify the concern is still present. Is the concern still present? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Test the system for normal operation. If no, the system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. Clear the DTCs. Repeat the self-test. Test the system for normal operation.

TEST D: WARNING INDICATOR ON WITH ENGINE RUNNING, SYSTEM IS CHARGING

1. Check For Fault Codes In PCM Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If DTC P0622 was retrieved, follow the NO direction. Are any PCM DTCs recorded? If no, go to next step. If yes, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
2. Check System For Overcharging Start engine. With engine running and all accessories turned off, measure voltage between battery terminals while varying engine speed. Is the voltage greater than 15.5 volts? If yes, perform «TEST C: SYSTEM OVERCHARGES (MORE THAN 15 VOLTS)»(ref-165592-S26105834642004083000000) . If no, go to next step.
3. Check Charging System PIDs Enter MONITOR PCM PIDs diagnostic mode on the diagnostic tool. With the engine running, monitor the generator output fault PID in the PCM. Does the PID read YES? If yes, go to next step. If no, see appropriate ANALOG INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT to diagnose the charging system warning indicator.
4. Check Generator Output Check generator output. See «GENERATOR LOAD TEST»(ref-165592-S04350352372004083000000) and «GENERATOR NO-LOAD TEST»(ref-165592-S22345607652004083000000) under ON-VEHICLE TESTING. Did the generator pass the component tests? If yes, go to next step. If no, install a new generator. See «GENERATOR»(ref-165592-S03554965692004083000000) under REMOVAL & INSTALLATION. Repeat the self-test. Test the system for normal operation.
5. Check For Correct PCM Operation Disconnect PCM connector. Check for corrosion and pushed-out pins. Connect PCM connector and make sure it seats correctly. Operate the system and verify the concern is still present. Is the concern still present? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Test the system for normal operation. If no, the system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. Clear the DTCs. Repeat the self-test. Test the system for normal operation.

TEST E: WARNING INDICATOR OFF WITH IGNITION ON

1. Check Charging System Warning Indicator Operation Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Enter the ACTIVE COMMANDS diagnostic mode on NGS tester. Using the ACTIVE COMMANDS, turn on the charging system warning indicator in the instrument cluster. Is the charging system warning indicator on? If yes, go to next step. If no, see appropriate ANALOG INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT to diagnose the charging system warning indicator.
2. Check For Correct PCM Operation Disconnect PCM connector. Check for corrosion and pushed-out pins. Connect PCM connector and make sure it seats correctly. Operate the system and verify the concern is still present. Is the concern still present? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Test the system for normal operation. If no, the system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. Clear the DTCs. Repeat the self-test. Test the system for normal operation.

TEST F: GENERATOR NOISY

1. Check For Accessory Drive Noise & Mounting Brackets Turn ignition off. Check the accessory drive belt for damage and correct installation. Check the accessory mounting brackets and generator pulley for looseness or misalignment. Is the accessory drive okay? If yes, go to next step. If no, repair as necessary. Test the system for normal operation.
2. Check Generator For Excessive Electrical Noise Disconnect generator 3-pin harness connector. Start engine. With the engine running, determine if the generator is still noisy. Is the noise still present? If yes, go to next step. If no, install a new generator. See «GENERATOR»(ref-165592-S03554965692004083000000) under REMOVAL & INSTALLATION. Test system for normal operation.
3. Check Generator For Mechanical Noise Turn all the accessories off. With the engine running, use a stethoscope or equivalent listening device to probe the generator for unusual mechanical noise. Is the generator the noise source? If yes, install a new generator. See «GENERATOR»(ref-165592-S03554965692004083000000) under REMOVAL & INSTALLATION. Test system for normal operation. If no, diagnose the source of the engine noise.

TEST G: RADIO INTERFERENCE

Note. If the Original Equipment Manufactured (OEM) audio unit has been replaced with an aftermarket unit, the vehicle may not pass this test. Return the vehicle to OEM condition before following this pinpoint test.

1. Verify Generator Is Source Of Radio Interference Start and run the engine. Tune the radio to a station where the interference is present. Turn ignition off. Disconnect generator B+ terminal. Start engine. With the engine running, determine if the interference is still present. Is the interference present with the generator disconnected? If yes, diagnose in-vehicle entertainment system. If no, install a new generator. See «GENERATOR»(ref-165592-S03554965692004083000000) under REMOVAL & INSTALLATION. Test system for normal operation.