Starters: Diagnosis Jaguar S-type I

PRELIMINARY INSPECTION

Verify customer complaint by operating suspected system. Visually inspect for obvious signs of mechanical and electrical damage. For mechanical damage, check for the following

1. Starter motor.
2. Battery.

For electrical damage, check for the following

1. Fuse No. 21 (30A) in the front power distribution fuse box and fuse No. 1 (5A) in the primary junction fuse box. See «FUSES & CIRCUIT BREAKERS»(ref-166074) article.
2. Starter relay.
3. Transmission range switch.
4. Inspect for loose or corroded connection, damaged wiring harnesses and/or switches. Check for broken or partially broken wires inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected.
5. Ensure any aftermarket electronic equipment is properly installed.

If a fault is found, repair as necessary. If no fault is found during a preliminary inspection, see SELF-DIAGNOSTIC SYSTEM for additional information.

SYMPTOMS

Note. For battery disconnect procedure, see BATTERY DISCONNECT PROCEDURE under MISCELLANEOUS. For battery reconnect procedure, see BATTERY RECONNECT PROCEDURE under MISCELLANEOUS.

Note. For circuit and connector identification, see WIRING DIAGRAMS and/or CONNECTOR IDENTIFICATION .

SELF-DIAGNOSTIC SYSTEM

Before performing any repairs, ensure Diagnostic Trouble Codes (DTC) are not set. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If any DTCs are present, diagnose accordingly. If no DTCs are present, diagnose by symptom, see SYSTEM TESTS .

Test Procedure

1. Check Battery - Check battery condition. See «BATTERY TESTS»(ref-164974-S26558937662004082100000) under ON-VEHICLE TESTING in GENERATORS & REGULATORS article in ELECTRICAL. Is the battery condition okay? If yes, go to next step. If no, install a NEW battery.
2. Check Starter Relay - Turn ignition switch to RUN position. Does the starter relay make an audible click? If yes, go to next step. If no, go to step 7 .
3. Check Starter For Battery Voltage - Measure voltage between starter battery cable terminal ST6 and ground. Is voltage greater than 10 volts? If yes, go to next step. If no, repair the battery cable starter circuit between the battery and the starter as necessary. Retest system for normal operation.
4. Check Starter Ground - Measure resistance between starter housing and ground. Is resistance less than 2 ohms? If yes, go to next step. If no, repair starter ground strap or ground connections as necessary. Retest system for normal operation.
5. Check Starter Signal Circuit For Voltage - With ignition switch in RUN position, measure voltage between starter connector ST5 and ground. Is voltage greater than 10 volts? If yes, install a NEW starter. See «STARTER»(ref-167192-S36390559142004100800000) under REMOVAL & INSTALLATION. Retest system for normal operation. If no, go to next step.
6. Check Battery Voltage To Starter Relay - Remove starter relay and measure voltage between starter relay socket terminal No. 30 and ground. Is the voltage greater than 10 volts? If yes, repair starter circuit between starter relay socket terminal No. 87 and starter connector ST5 as necessary. Retest system for normal operation. If no, check fuse No. 21 (30A) in the front power distribution fuse box. If fuse No. 21 is okay, repair starter relay circuit between fuse No. 21 and starter relay socket terminal No. 30 as necessary. Retest system for normal operation. If fuse No. 21 is blown, install a NEW fuse and retest system for normal operation.
7. Check Ignition Voltage To Starter Relay - Remove starter relay. With the transmission in PARK or NEUTRAL position, measure voltage between starter relay socket terminal No. 86 and ground. Is voltage greater than 10 volts? If yes, go to next step. If no, go to step 10 .
8. Check Ground Supply To Starter Relay - Measure resistance between starter relay socket terminal No. 85 and ground. Is the resistance less than 5 ohms? If yes, install a NEW starter relay and retest system for normal operation. If no, go to next step.
9. Check Ground Supply Circuit - Measure resistance between starter relay socket terminal No. 85 and instrument pack harness connector FC15 terminal No. 18. Is resistance less than 5 ohms? If yes, diagnose anti-theft system. See DOOR LOCKS & ANTI-THEFT SYSTEMS article in ACCESSORIES & EQUIPMENT. If no, repair ground circuit between starter relay socket terminal No. 85 and instrument pack harness connector FC15 terminal No. 18 as necessary. Retest system for normal operation.
10. Check Fuse No. 1 - Check condition fuse No. 1 in the primary junction fuse box. Is fuse No. 1 okay? If yes, go to step 12 . If no, go to next step.
11. Check For Short To Ground - Measure resistance between starter relay socket terminal No. 86 and ground. Is resistance greater than 10,000 ohms? Install a NEW fuse. If no, repair short to ground between fuse No. 1 in the primary junction fuse box and starter relay socket terminal No. 86. Retest system for normal operation.
12. Check Transmission Range Switch - Disconnect transmission range sensor harness connector GB6. Check resistance between transmission range sensor terminals No. 10 and No. 12 with gearshift selector in PARK or NEUTRAL position. Is resistance less than 5 ohms? If yes, check circuitry between primary junction fuse box and starter relay. Retest system for normal operation. If no, install a NEW transmission range sensor and retest system for normal operation.

1. Check Voltage Drop On Positive Battery Cable - Measure voltage between starter motor battery cable terminal and positive battery terminal with ignition key in START position. Is voltage less than 0.5 volts? If yes, go to next step. If no, clean and tighten all positive battery cable connections. Retest system for normal operation. If all positive battery cable connections are clean and tight and condition remains, install a NEW positive battery cable.
2. Check Voltage Drop on Ground Circuit - Measure voltage between starter motor housing and battery negative terminal with ignition key in START position. Is voltage less than 0.5 volts? If yes, diagnose battery and charging system. See «GENERATORS & REGULATORS»(ref-164974) article in ELECTRICAL. If battery and charging system is okay, starter may be faulty. If no, clean and tighten all negative battery cable connections, starter motor mounting and body to engine ground straps. Retest system for normal operation. If all negative battery cable connections are clean and tight and condition remains, install a NEW negative battery cable.

Note. For battery disconnect procedure, see BATTERY DISCONNECT PROCEDURE under MISCELLANEOUS. For battery reconnect procedure, see BATTERY RECONNECT PROCEDURE under MISCELLANEOUS.