DIAGNOSIS AND TESTING

Transcription

1 303-06B-1 DIAGNOSIS AND TESTING Starting System Special Tool(s) 73 III Automotive Meter 105-R0057 or equivalent B-1 2. Inspect the system to determine if any of the following mechanical or electrical concerns apply. Visual Inspection Chart Mechanical Starter motor mounting Starter relay mounting Electrical Battery condition Electrical connections at the switches, relay and solenoid Fuse 20 ARBST Battery and Electrical Fuse 22 System Tester or equivalent 3. If the concern(s) remains after the inspection and verification, determine the symptoms. GO to Symptom Chart. Inspection and Verification 1. WARNING: When servicing the starter motor or carrying out other underhood work in the vicinity of the starter motor, be aware that the heavy gauge battery input lead at the starter solenoid is electrically hot at all times. Failure to follow these instructions may result in personal injury. Verify the vehicle owner s original concern by operating the system to duplicate the condition. Symptom Chart SYMPTOM CHART Condition Possible Sources Action The engine does not crank Battery. GO to Pinpoint Test A. and the relay does click Fuse(s). Starter motor/solenoid. Ignition switch. Circuit. The engine does not crank Fuse. GO to Pinpoint Test B. and the relay does not click Powertrain control module (PCM) fuses. Battery. Starter relay. Ignition switch. Digital transmission range (TR) sensor. Starter solenoid. Clutch pedal position (CPP) switch. Circuit. Copyright 2003, Ford Motor Company Last updated: 9/30/2004

2 303-06B-2 SYMPTOM CHART Condition Possible Sources Action The engine cranks slowly Battery. GO to Pinpoint Test C. Starter motor/solenoid. Circuit. Unusual starter noise Starter mounting. GO to Pinpoint Test D. Starter motor. Incorrect starter drive engagement. The starter spins but the Worn or damaged starter GO to Pinpoint Test E. engine does not crank motor. Damaged flywheel ring gear B-2 Pinpoint Tests A1 PINPOINT TEST A: THE ENGINE DOES NOT CRANK AND THE RELAY DOES CLICK CHECK THE VOLTAGE TO THE STARTER RELAY Measure the voltage between the starter relay pin 30, circuit 2037 (RD) and ground. A2 GO to A2. REPAIR circuit 2037 (RD) for an open. Is the voltage greater than 12.5 volts? TEST the system for normal operation. CHECK THE VOLTAGE TO THE STARTER MOTOR SOLENOID Measure the voltage between the starter motor solenoid positive terminal and ground. GO to A3. REPAIR circuit 2037 (RD) for an open. Is the voltage 12.5 volts or greater? TEST the system for normal operation.

3 303-06B-3 A B-3 PINPOINT TEST A: THE ENGINE DOES NOT CRANK AND THE RELAY DOES CLICK MANUALLY JUMP THE STARTER MOTOR Connect one end of a fused (15A) jumper wire to the positive terminal of the battery and touch the other end to the starter solenoid S-terminal. A4 B1 GO to A4. INSTALL a new starter. TEST the system Does the starter solenoid engage? for normal operation. TEST THE STARTER MOTOR RELAY Carry out the relay component test on the starter motor relay. Refer to the relay component test in this section. REPAIR circuit 113 (YE/LB) for an open. Does the starter motor relay test good? TEST the system for normal operation. INSTALL a new starter motor relay. TEST the system for normal operation. PINPOINT TEST B: THE ENGINE DOES NOT CRANK AND THE RELAY DOES NOT CLICK CHECK THE STARTER MOTOR RELAY COIL FOR VOLTAGE Disconnect: Starter Motor Relay. Key in START position. Measure the voltage between the starter motor relay pin 86, circuit 1093 (TN/RD) (for manual vehicles), or circuit 33 (WH/PK) (for automatic vehicles) and ground, while holding the key in the START position. B2 GO to B7. For automatic transmissions, GO to B4. Is the voltage greater than 10 volts? For manual transmissions, GO to B2. CHECK CIRCUIT 33 (WH/PK) FOR VOLTAGE AT THE CLUTCH SWITCH OR JUMPER Disconnect: Clutch Pedal Switch C257. Key in START position.

4 303-06B B-4 PINPOINT TEST B: THE ENGINE DOES NOT CRANK AND THE RELAY DOES NOT CLICK B2 CHECK CIRCUIT 33 (WH/PK) FOR VOLTAGE AT THE CLUTCH SWITCH OR JUMPER Measure the voltage between clutch pedal switch C257 pin 1, circuit 33 (WH/PK) and ground, while holding the key in the START position. B3 GO to B3. Is the voltage greater than 10 volts? GO to B4. CHECK CIRCUIT 1093 (TN/RD) FOR AN OPEN Measure the resistance between clutch pedal switch C257 pin 2, circuit 1093 (TN/RD) and the starter motor relay pin 86, circuit 1093 (TN/RD). INSTALL a new clutch pedal switch. TEST the system for normal operation. REPAIR circuit 1093 (TN/RD). TEST the Is the resistance less than 5 ohms? system for normal operation. B4 CHECK FOR VOLTAGE AT FUSE 31 Disconnect: Fuse #31. Key in START position.

5 303-06B B-5 PINPOINT TEST B: THE ENGINE DOES NOT CRANK AND THE RELAY DOES NOT CLICK B4 CHECK FOR VOLTAGE AT FUSE 31 Measure the voltage between the central junction box fuse 31, circuit 1522 (DG) and ground, while holding the key in the START position. B5 REPAIR circuit 1522 (DG). TEST the system for normal operation. Is the voltage greater than 10 volts? GO to B5. CHECK CIRCUIT 1050 (LG/VT) FOR VOLTAGE Disconnect: Ignition Switch C250. Key in ON position. Measure the voltage between ignition switch connector C250 pin B4, circuit 1050 (LG/VT) and ground. B6 B7 GO to B6. REPAIR circuit 1050 (LG/VT). TEST the Is the voltage greater than 10 volts? system for normal operation. CHECK THE IGNITION SWITCH Carry out the ignition switch component test. Does the ignition switch test good? REPAIR circuit 1522 (DG). TEST the system for normal operation. INSTALL a new ignition switch. TEST the system for normal operation. CHECK THE RELAY GROUND CIRCUIT FOR AN OPEN

6 303-06B B-6 PINPOINT TEST B: THE ENGINE DOES NOT CRANK AND THE RELAY DOES NOT CLICK B7 CHECK THE RELAY GROUND CIRCUIT FOR AN OPEN Measure the voltage between the starter motor relay pin 85, circuit 57 (BK) (for manual vehicles) or circuit 262 (BN/PK) (for automatic vehicles) and pin 86, circuit 1093 (TN/RD) or circuit 33 (WH/PK). B8 INSTALL a new starter motor relay. TEST the system for normal operation. Manual only REPAIR circuit 57 (BK). TEST the system for normal operation. Is the voltage greater than 10 volts? Automatic only GO to B8. CHECK CIRCUIT 262 (BN/PK) Disconnect: PCM C1381a. Measure the resistance between the starter motor relay socket pin 85, circuit 262 (BN/PK) and the PCM C1381a pin 4, circuit 262 (BN/PK). INSTALL a new PCM. TEST the system for normal operation. REPAIR circuit 262 (BN/PK). CLEAR the DTCs. TEST the system for normal Is the resistance less than 5 ohms? operation. C1 PINPOINT TEST C: THE ENGINE CRANKS SLOWLY NOTE: Before beginning this test, be sure that the battery is tested and fully charged. CHECK THE VOLTAGE TO THE STARTER

7 303-06B-7 C1 PINPOINT TEST C: THE ENGINE CRANKS SLOWLY CHECK THE VOLTAGE TO THE STARTER Measure the voltage between the starter motor solenoid positive terminal and ground B-7 C2 D1 D2 E1 GO to C2. REPAIR the circuit between the battery and the starter solenoid. CLEAN and TIGHTEN the connections at the battery terminals. TEST the system for normal Is the voltage 12.5 volts or greater? operation. CHECK THE MOTOR GROUND CIRCUIT Carry out the Motor Ground Circuit test. Refer to Component Tests in this section. INSTALL a new starter motor. TEST the Is the ground OK? system for normal operation. REPAIR the ground circuit as necessary. TEST the system for normal operation. PINPOINT TEST D: UNUSUAL STARTER NOISE CHECK THE STARTER MOTOR MOUNTING Inspect the starter motor mounting brackets for cracks. Check the starter motor mounting bolts for looseness. GO to D2. Is the starter motor mounted correctly? REINSTALL the starter motor correctly. INSPECT THE STARTER MOTOR Remove the starter motor. Inspect the starter motor for damage. INSTALL a new starter motor. TEST the Is the starter motor damaged? system for normal operation. CHECK the starter drive. REFER to Component Tests, Starter Drive Test in this section. INSTALL a new starter motor. TEST the system for normal operation. PINPOINT TEST E: THE STARTER SPINS BUT THE ENGINE DOES NOT CRANK CHECK THE FLYWHEEL Remove the starter motor. Inspect the flywheel and the drive pinion for damage or INSTALL a new starter motor and excessive wear. flywheel. TEST the system for normal Is the flywheel or the drive pinion worn or damaged? operation. INSTALL a new starter.

8 303-06B B-8 Component Tests 2. The pinion drive should free-wheel in one Starter Motor Load Test direction and lock to the armature shaft in the other. NOTE: The batteries must be fully charged before 3. If the pinion drive free-wheels in both carrying out a starter load test. directions, Install a new starter motor. 1. Set the parking brake and shift the transmission into the NEUTRAL position. Starter Motor -Load Test 2. Remove Fuse 17 from the engine compartment 1. Connect a fully charged battery to the starter. fuse box. 2. Connect the Alternator, Regulator, Battery and 3. Connect the Alternator, Regulator, Battery and Starter Tester (ARBST) as illustrated. Starter Tester (ARBST). Follow the 3. Connect a remote starter switch between the manufacturer s supplied instructions. starter solenoid Terminal S and the positive 4. Connect a remote starter switch across the battery terminal post. starter relay S-terminal and the battery positive 4. Press the remote starter switch. The pinion terminal post. should shift to the crank position and the motor 5. Turn the ignition switch to the RUN position. should run smoothly. 6. Crank the engine and record the voltmeter 5. While the starter motor is running, record the reading. voltmeter and ammeter readings. 7. Turn the carbon pile control knob until the 6. The voltage reading should be greater than 11.0 voltmeter indicates the same reading recorded volts and the amperage should be no more than during cranking the engine. Record the ammeter 170 amps. reading. 7. If voltage is lower than specified or amperage 8. Compare the ammeter reading with is higher than specified, refer to the results specifications. chart below to determine possible cause and corrective action. Starter Motor Drive Pinion Test 1. Rotate the pinion drive clockwise and counterclockwise. Starter Motor -Load Test Results Test Result Probable Source Action to Take rmal Current and Speed Cranking motor OK. RECHECK the battery, switches and wiring, including voltage drop tests, if cranking motor operation on the engine is slow or sluggish. Current Flow with Test Circuit Solenoid contacts stuck closed. CARRY OUT the Starter Solenoid Switch Open Component Test. Failure to Operate with Very Low Open solenoid winding. CARRY OUT the Starter Solenoid or Current Component Test. Open field circuit. Open armature coil(s) or high insulation between commutator bars. Broken brush spring(s) or worn brushes. Failure to Operate with High Frozen bearing, or other damage to Current drivetrain. Direct ground in terminals or fields.

9 303-06B-9 Starter Motor -Load Test Results Test Result Probable Source Action to Take B-9 Low Speed with High Current Excessive friction in bushings or gear reduction unit, bent armature shaft or loose pole shoe, bent driveshaft. Shorted armature. Grounded armature or fields. Low Speed with rmal (or Low) High internal electrical resistance Current caused by poor connections, defective leads or dirty commutator. Open solenoid winding. Open field circuit. Open field circuit. Broken brush spring(s) or worn brushes. CARRY OUT the Starter Solenoid Component Test. High Speed with High Current Shorted fields. Starter Motor Motor Feed Circuit Voltage Drop Test 1. This test is carried out to determine if slow cranking is caused by high resistance in the starter motor circuit wiring. 12. If the reading at the starter solenoid M-terminal is still higher than 0.5 volt or the reading at the B-terminal is lower, carry out the Starter Solenoid Component Test. If no change is noted, install a new positive battery cable lead. 2. The voltage drop test can only be carried out Starter Motor Motor Ground Circuit with the starter motor on the vehicle. Voltage Drop Test 3. Disconnect the fuel pump electrical connector. NOTE: A slow cranking condition can also be 4. Connect the positive lead of the 73 Digital caused by high resistance in the ground circuit. Multimeter to the battery positive (+) post, and 1. Disconnect the wiring from the fuel pump the negative lead to the starter solenoid electrical connector.. M-terminal. 2. Connect the Digital Volt-Ohmmeter positive 5. Connect a remote starter switch between the lead to the starter motor housing. starter solenoid S-terminal and the positive 3. Connect the Digital Volt-Ohmmeter negative battery terminal post. lead to the battery negative (-) terminal. 6. Press the remote starter switch and record the 4. Connect a remote starter switch between the voltage reading. starter solenoid S-terminal and the positive 7. The voltage reading should be 0.5 volt or less. battery terminal post. A reading higher than 0.5 volt indicates high 5. Press the remote starter switch and record the resistance. voltage reading. 8. Repeat the test on the starter solenoid 6. The voltage reading should be 0.2 volt or less. B-terminal. If the voltage reading is higher, remove and 9. If the readings are higher than 0.5 volt, remove clean the negative cable connections at the the wiring from the starter solenoid. battery, starter motor and the body. 10. Clean and inspect each wire connector and the 7. Retest the system. If readings are still higher starter solenoid terminals. 11. Install the wires onto the starter solenoid and retest. than 0.2 volt, test each individual negative cable.

10 303-06B B-10 Starter Solenoid An extremely high resistance reading 1. Disconnect the battery negative cable. indicates a break or fault in winding continuity. A very low resistance reading 2. Using the Digital Multimeter, check the indicates a short or ground in the winding windings of the solenoid as follows: circuit. Either condition is cause for Measure the resistance between the starter installation of a new solenoid assembly. motor ground terminal and the solenoid case. The resistance reading should be approximately 0.95 ohms.