Starting System: Diagnosis Jeep Cherokee II рестайлинг

ON-VEHICLE TESTING

CRANKING TEST

Note. Ensure engine is at normal operating temperature. High viscosity oil, extreme cold temperatures, or tight engine will increase amperage draw.

1. Using a battery load tester, connect positive and negative leads to battery. Connect inductive ammeter pick-up to positive battery cable. Ensure all lights and accessories are off. Place A/T in Park, or M/T in Neutral. Apply parking brake. Unplug Automatic Shut Down (ASD) relay from Power Distribution Center (PDC). Refer to PDC cover for relay location. PDC is located in engine compartment. On M/T models, depress clutch pedal. CAUTION: During cranking, DO NOT draw battery voltage down to less than 9.6 volts. Use care not to overheat starter.
2. Crank engine and observe voltmeter reading. If voltage drops below 9.6 volts, recharge and test battery. Retest voltage. If voltage remains less than 9.6 volts, bench test starter. See «BENCH TESTING»(ref-669-S42085894742000031300000) . If voltage remains above 9.6 volts, observe amperage reading. If amperage draw is less than specified, perform circuit resistance tests. See «STARTER SPECIFICATIONS»(ref-669-S07588728262000031300000) table. Also see «CIRCUIT RESISTANCE TESTS»(ref-669-S18563021322000031300000) .
3. If voltage reads more than 12.5 volts, and starter does not turn, problem is in battery, relay, solenoid, ignition switch, park/neutral switch, clutch switch or wiring. Check each component until problem is found. If voltage is more than 12.5 volts and starter cranks very slowly, perform circuit resistance tests. See «CIRCUIT RESISTANCE TESTS»(ref-669-S18563021322000031300000) .

Battery Connection Resistance Test

Connect voltmeter positive lead to negative battery cable clamp. Connect voltmeter negative lead to negative battery post. Crank engine and observe voltmeter reading. If voltage is greater than 0.2 volt, repair poor contact between cable clamp and post. Perform same procedure to positive battery post and cable clamp.

Ground Connection Resistance Test

Connect voltmeter negative lead to negative battery post. Connect voltmeter positive lead to engine block, near negative battery cable grounding point. Crank engine and observe voltmeter reading. If voltage is greater than 0.2 volt, repair poor ground connection or replace ground cable.

Starter Ground Connection Resistance Test

Connect voltmeter negative lead to negative battery post. Connect voltmeter positive lead to starter housing. Crank engine and observe voltmeter reading. If voltmeter reading indicates more than 0.2 volt, repair poor starter-to-ground connection.

Positive Battery Cable Resistance Test

1. Remove starter heat shield (if equipped) to gain access to starter solenoid connections. Connect voltmeter negative lead to starter solenoid battery terminal and voltmeter positive lead to positive battery post.
2. Crank engine and observe voltmeter reading. If voltage reads more than 0.2 volt, correct poor connection between battery cable and starter solenoid or replace positive battery cable.

SOLENOID CIRCUIT TEST

Note. Perform this procedure before testing starter relay circuit and starter relay. Ensure transmission is in Park (A/T) or Neutral (M/T) and parking brake is applied.

1. Ensure battery is fully charged. Ensure solenoid connections are not loose or corroded. Remove starter relay from Power Distribution Center (PDC). Refer to PDC cover for proper relay location. PDC is located in engine compartment.
2. Connect a remote starter switch or jumper wire between starter relay connector terminal No. 87 and positive battery post. (Scheme 1)or (Scheme 2). If engine cranks, solenoid and starter are good. Go to «STARTER RELAY CIRCUIT TEST»(ref-669-S30014271412000031300000).
3. If engine fails to crank, or if solenoid chatters, check wiring and connectors from starter relay connector to starter solenoid terminal for loose or corroded connections. Clean and retest. If engine still fails to crank, remove starter and proceed to «SOLENOID TEST»(ref-669-S33272714762000031300000) under BENCH TESTING.

Scheme 1

Scheme 2

STARTER RELAY TEST

Note. Perform SOLENOID CIRCUIT TEST under ON-VEHICLE TESTING before testing starter relay.

1. Remove starter relay from Power Distribution Center (PDC). PDC is located in engine compartment. Refer to PDC label for starter relay identification.
2. Using an ohmmeter, check for continuity between starter relay terminals No. 30 and 87A. (Scheme 1)or (Scheme 2). If no continuity exists, replace starter relay. Check for continuity between starter relay terminals No. 30 and 87. If continuity exists, replace starter relay. If relay tests as specified, go to next step.
3. Check resistance between starter relay terminals No. 85 and 86. If resistance is not 70-80 ohms, replace starter relay. If resistance is okay, go to next step.
4. Connect a 12-volt power source to starter relay terminals No. 85 and 86. Continuity should exist between starter relay terminals No. 30 and 87. No continuity should exist between starter relay terminals No. 30 and 87A. Replace starter relay if it does not test as specified. If starter relay tests as specified, go to «STARTER RELAY CIRCUIT TEST»(ref-669-S30014271412000031300000).

STARTER RELAY CIRCUIT TEST

Note. Perform SOLENOID CIRCUIT TEST under ON-VEHICLE TESTING before testing starter relay circuit.

1. Ensure battery is fully charged. Remove starter relay from Power Distribution Center (PDC). Refer to PDC cover for proper relay location. PDC is located in engine compartment. Depress clutch pedal on M/T models.
2. Connect a jumper wire between starter relay connector terminals No. 30 and 87. (Scheme 1)or (Scheme 2). If engine does not crank, go to «SOLENOID TEST»(ref-669-S33272714762000031300000) under BENCH TESTING. If engine cranks, go to next step.
3. Turn ignition on. Check for battery voltage at starter relay connector terminal No. 30. If voltage is not present, repair open in wiring from starter relay connector to battery.
4. If voltage is present at starter relay connector terminal No. 30, ensure battery voltage is also present at starter relay connector terminal No. 86. Check for voltage with ignition switch in START position. If voltage is not present, go to next step. If voltage is present, circuit is okay. Go to step 6.
5. If voltage is not present at starter relay connector terminal No. 86, repair open or short in wiring from ignition switch to starter relay connector. If circuit to ignition switch is okay, check ignition switch. See «IGNITION SWITCH TEST»(ref-669-S10554619852000031300000) under ON-VEHICLE TESTING.
6. Check for continuity to ground at starter relay connector terminal No. 85. If continuity exists, circuit is okay. If continuity does not exist, go to next step.
7. If vehicle is equipped with an A/T, check for an open or short to park/neutral position switch. See «PARK/NEUTRAL POSITION SWITCH»(ref-669-S12476140962000031300000) under ON-VEHICLE TESTING. If vehicle is equipped with a M/T, repair circuit to ground as required.

IGNITION SWITCH TEST

1. Disconnect negative battery cable. Remove ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. With ignition switch in ON position, check for continuity between ignition switch terminals No. 1 and 7 (terminals No. 3 and 10 on Wrangler). See «WIRING DIAGRAMS»(ref-669-S37266396222000031300000) . If continuity exists, replace ignition switch. If continuity does not exist, go to next step.
2. With ignition switch in START position, check for continuity between ignition switch terminals No. 1 and 7 (terminals No. 3 and 10 on Wrangler). See WIRING DIAGRAMS. If continuity exists, ignition switch is okay. If continuity does not exist, replace ignition switch.

Note. For additional information, refer to TEST NS-1A in appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

SOLENOID TEST

1. Remove starter. Using an ohmmeter, test for continuity between field terminal (large terminal connected to starter body) and solenoid terminal (small terminal). Continuity should exist.
2. Test for continuity between solenoid terminal and solenoid housing. Continuity should exist. If continuity does not exist in either test, solenoid has open circuit. Replace solenoid.