| Diagnosis and Testing Worldwide Diagnostic System (WDS) Principles of Operation The starter motor function is controlled by a starter relay. The starter relay is operated by the ignition switch. Battery voltage is supplied to the ignition switch from battery junction box (BJB) fuse F17. When the ignition switch is turned to position III, battery voltage is supplied to the starter relay coil. The starter relay coil circuit is completed by a ground circuit through the powertrain control module (PCM). The ground circuit will only be available when the PCM receives the correct signal from the passive anti-theft system (PATS). When the starter relay coil is energized, the starter relay contacts close and battery voltage is supplied to the starter motor solenoid circuit from BJB fuse F15. The starter motor solenoid circuit is completed by a ground circuit through the starter motor casing. The starter motor solenoid has two functions. The first is to supply the starter motor with a high energy switch between the battery positive terminal and the starter motor windings. The second is to act as a mechanical clutch between the starter motor drive gear and the flywheel ring gear. Battery voltage is supplied to the starter motor solenoid contact through a fused wire. The ground circuit is completed using the starter motor casing and the engine/transmission ground wire. Inspection and Verification - Verify the customer concern.
- Visually inspect for obvious signs of mechanical or electrical damage.
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step
- If the cause is not visually evident, verify the symptom and refer to the Symptom Chart.
Visual Inspection Chart | Mechanical | Electrical | | | - Fuse(s)
- Wiring harness(es)
- Electrical connector(s)
- Relay(s)
- Switch(es)
- Battery
| Symptom Chart | Symptom | Possible Sources | Action | | The engine does not crank and the relay does not click | * Battery | * REFER to: Charging System (414-00, Diagnosis and Testing). | | * Circuit(s) * Starter relay * Ignition switch * PCM * BJB | * | | * PATS | * REFER to: Anti-Theft - Passive (419-01B, Diagnosis and Testing). | | The engine does not crank but the relay clicks | * Battery | * REFER to: Charging System (414-00, Diagnosis and Testing). | | * Circuit(s) * Starter relay * Starter motor | * | | The engine cranks slowly | * Battery | * REFER to: Charging System (414-00, Diagnosis and Testing). | | * Battery cable * Starter motor | * | | Unusual starter motor noise | * Starter motor | * INSPECT the starter motor for alignment or cracked casing. Make sure the mounting bolts are tightened. If necessary, INSTALL a new starter motor.
REFER to: Starter Motor (303-06A Starting System - 2.0L Duratec-HE (MI4), Removal and Installation) /
Starter Motor (303-06B Starting System - 2.5L Duratec-ST (VI5), Removal and Installation) /
Starter Motor (303-06C Starting System - 1.8L Duratorq-TDCi (Kent) Diesel, Removal and Installation) /
Starter Motor (303-06D Starting System - 2.0L Duratorq-TDCi (DW) Diesel, Removal and Installation).
TEST the system for normal operation. | | * Flywheel ring gear | * CHECK the flywheel ring gear. INSTALL a new flywheel ring gear as necessary. | | The starter motor spins but the engine does not crank | * Starter motor | * REMOVE the starter motor. INSPECT the starter motor gear for damage. INSTALL a new starter motor as necessary.
REFER to: Starter Motor (303-06A Starting System - 2.0L Duratec-HE (MI4), Removal and Installation) /
Starter Motor (303-06B Starting System - 2.5L Duratec-ST (VI5), Removal and Installation) /
Starter Motor (303-06C Starting System - 1.8L Duratorq-TDCi (Kent) Diesel, Removal and Installation) /
Starter Motor (303-06D Starting System - 2.0L Duratorq-TDCi (DW) Diesel, Removal and Installation).
TEST the system for normal operation. | | * Flywheel ring gear | * INSPECT the flywheel ring gear for missing teeth. CHECK the starter motor for correct mounting. If the concern persists, INSTALL a new starter motor.
REFER to: Starter Motor (303-06A Starting System - 2.0L Duratec-HE (MI4), Removal and Installation) /
Starter Motor (303-06B Starting System - 2.5L Duratec-ST (VI5), Removal and Installation) /
Starter Motor (303-06C Starting System - 1.8L Duratorq-TDCi (Kent) Diesel, Removal and Installation) /
Starter Motor (303-06D Starting System - 2.0L Duratorq-TDCi (DW) Diesel, Removal and Installation).
TEST the system for normal operation. | Pinpoint Tests NOTE:Use a digital multimeter for all electrical measurements. | PINPOINT TEST A : THE ENGINE DOES NOT CRANK AND THE RELAY DOES NOT CLICK | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: CHECK THE STARTER RELAY COIL FOR VOLTAGE | | | 1 Disconnect Starter Relay R1. | | | 2 Ignition switch in position III. | | | 3 Measure the voltage between the BJB starter relay R1 connector pin 1, circuit CDC35D (BU/WH), harness side and ground. | | | Is the voltage greater than 10 volts? Yes No | | A2: CHECK CIRCUIT CDC35D (BU/WH) AND CDC35F (BU/WH) FOR CONTINUITY | | | 1 Ignition switch in position 0. | | | 2 Disconnect Ignition Switch C2DC32. | | | 3 Measure the resistance between the BJB starter relay R1 connector pin 1, circuit CDC35D (BU/WH), harness side and the ignition switch C2DC32 pin 7, circuit CDC35F (BU/WH), harness side. | | | Is the resistance less than 1 ohm? Yes INSTALL a new ignition switch. TEST the system for correct operation. No REPAIR circuit CDC35D (BU/WH) or circuit CDC35F (BU/WH) as necessary. TEST the system for normal operation. | | A3: CHECK THE STARTER RELAY COIL FOR GROUND | | | 1 Measure the resistance between the BJB starter relay R1 connector pin 2, circuit CDC12A (YE), and ground. | | | Is the resistance less than 1 ohm? Yes INSTALL a new starter relay. TEST the system for normal operation. No For vehicles with 1.8L Duratorq TDCi (Kent) Diesel and 2.0L Duratorq TDCi (DW) Diesel, GO to A4. For vehicles with 2.0L Duratec HE (MI4), GO to A5. For vehicles with 2.5L Duratec ST (VI5), GO to A6. | | A4: CHECK CIRCUIT CDC12A (YE) FOR CONTINUITY | | | 1 Ignition switch in position 0. | | | 2 Disconnect PCM C1E108-K. | | | 3 Measure the resistance between the BJB starter relay R1 connector pin 2, circuit CDC12A (YE) and the PCM C1E108-K pin K2, circuit CDC12A (YE), harness side. | | | Is the resistance less than 1 ohm? Yes Using the WDS, CHECK for current DTCs. CORRECT all DTCs. TEST the system for normal operation. If the concern persists, INSTALL a new PCM. TEST the system for normal operation. No REPAIR the circuit. TEST the system for normal operation. If the concern persists, INSTALL a new BJB. TEST the system for normal operation. | | A5: CHECK CIRCUIT CDC12A (YE) FOR CONTINUITY | | | 1 Ignition switch in position 0. | | | 2 Disconnect PCM C1E104-E. | | | 3 Measure the resistance between the BJB starter relay R1 connector pin 2, circuit CDC12A and the PCM C1E104-E pin L2, circuit CDC12A (YE), harness side. | | | Is the resistance less than 1 ohm? Yes Using the WDS, CHECK for current DTCs. CORRECT all DTCs. TEST the system for normal operation. If the concern persists, INSTALL a new PCM. TEST the system for normal operation. No REPAIR the circuit. TEST the system for normal operation. If the concern persists, INSTALL a new BJB. TEST the system for normal operation. | | A6: CHECK CIRCUIT CDC35G (BU/WH) FOR CONTINUITY | | | 1 Ignition switch in position 0. | | | 2 Disconnect PCM C1E108-B. | | | 3 Measure the resistance between the BJB starter relay R1 connector pin 1, circuit CDC35G (BU/WH), harness side and the PCM C1E108-B pin 17, circuit CDC35G (BU/WH), harness side. | | | Is the resistance less than 1 ohm? Yes No REPAIR circuit CDC35G (BU/WH). TEST the system for normal operation. If the concern persists, INSTALL a new BJB. TEST the system for normal operation. | | A7: CHECK CIRCUIT CDC12A (YE) FOR CONTINUITY | | | 1 Disconnect BJB C1E108-B. | | | 2 Measure the resistance between the BJB starter relay R1 connector pin 2, circuit CDC12A (YE), harness side and the PCM C1E108-B pin 9, circuit CDC12A (YE), harness side. | | | Is the resistance less than 1 ohm? Yes Using the WDS, CHECK for current DTC's. CORRECT all DTC's. TEST the system for normal operation. If the concern persists, INSTALL a new PCM. TEST the system for normal operation. No REPAIR circuit CDC12A (YE). TEST the system for normal operation. If the concern persists, INSTALL a new BJB. TEST the system for normal operation. | | PINPOINT TEST B : THE ENGINE DOES NOT CRANK BUT THE RELAY CLICKS | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: CHECK CIRCUIT CDC35B (GN/RD) FOR VOLTAGE | | | 1 Ignition switch in position III. | | | 2 Measure the voltage between the starter motor solenoid C1DC35-B-1 circuit CDC35B (GN/RD), component side and ground. | | | Is the voltage greater than 10 volts? Yes No | | B2: CHECK CIRCUIT SBF01A (RD) FOR VOLTAGE DROP | | | 1 Ignition switch in position III. | | | 2 Measure the voltage between starter motor solenoid C1DC35-A-1 circuit SBF01A (RD), component side and the battery positive terminal. | | | Is the voltage less than 2 volts? Yes CLEAN and TIGHTEN all battery positive cable connections. TEST the system for normal operation. If the concern persists, INSTALL a new starter motor.
REFER to: Starter Motor (303-06A Starting System - 2.0L Duratec-HE (MI4), Removal and Installation) /
Starter Motor (303-06B Starting System - 2.5L Duratec-ST (VI5), Removal and Installation) /
Starter Motor (303-06C Starting System - 1.8L Duratorq-TDCi (Kent) Diesel, Removal and Installation) /
Starter Motor (303-06D Starting System - 2.0L Duratorq-TDCi (DW) Diesel, Removal and Installation).
TEST the system for normal operation. No CLEAN and TIGHTEN all battery positive cables connections. TEST the system for normal operation. If the concern persists, INSTALL a new battery to starter motor solenoid cable. TEST the system for normal operation. | | B3: CHECK THE STARTER RELAY CONTACT CIRCUIT FOR VOLTAGE | | | 1 Disconnect Starter Relay R1. | | | 2 Measure the voltage between the BJB starter relay R1 connector pin 3 and ground. | | | Is the voltage greater than 10 volts? Yes No INSTALL a new BJB. TEST the system for normal operation. | | B4: CHECK CIRCUIT CDC35 (BU/WH) FOR CONTINUITY | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the BJB starter relay R1 connector pin 5 and the starter motor solenoid C1DC35-B pin 1, circuit CDC35B (BU/WH). | | | Is the resistance less than 1 ohm? Yes INSTALL a new starter relay. TEST the system for normal operation. If the concern persists, INSTALL a new BJB. TEST the system for correct operation. No REPAIR circuit CDC35A (BU/WH) or circuit CDC35B (BU/WH) as necessary. TEST the system for correct operation. | | PINPOINT TEST C : THE ENGINE CRANKS SLOWLY | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | C1: CHECK THE BATTERY VOLTAGE AND CONDITION | | | 1 CHECK the battery using a battery tester. | | | Is the battery voltage and condition OK? Yes No CHARGE or install a new battery as required. CHECK the charging system using WDS. TEST the system for normal operation. | | C2: CHECK CIRCUIT SBF01A (RD) FOR VOLTAGE DROP | | | 1 Ignition switch in position III. | | | 2 Measure the voltage between starter motor solenoid C1DC35-A-1 circuit SBF01A (RD), component side and the battery positive terminal. | | | Is the voltage less than 2 volts? Yes No CLEAN and TIGHTEN all battery positive cables connections. TEST the system for normal operation. If the concern persists, INSTALL a new battery to starter motor solenoid cable. TEST the system for normal operation. | | C3: CHECK FOR GROUND CONNECTION | | | 1 Ignition switch in position III. | | | 2 Measure the voltage between the starter motor housing and the battery negative terminal. | | | Is the voltage less than 2 volts? Yes INSTALL a new starter motor.
REFER to: Starter Motor (303-06A Starting System - 2.0L Duratec-HE (MI4), Removal and Installation) /
Starter Motor (303-06B Starting System - 2.5L Duratec-ST (VI5), Removal and Installation) /
Starter Motor (303-06C Starting System - 1.8L Duratorq-TDCi (Kent) Diesel, Removal and Installation) /
Starter Motor (303-06D Starting System - 2.0L Duratorq-TDCi (DW) Diesel, Removal and Installation).
TEST the system for normal operation. No CLEAN and TIGHTEN all battery negative cable connections and starter motor mountings. TEST the system for normal operation. If the concern persists, INSTALL a new battery negative cable. TEST the system for normal operation. | | |
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