Starter Motor: Testing and Inspection
Starter TestNOTE: The air temperature must be between 59 and 100° F (15 and 38° C) before testing.
Recommended Procedure:
^ Use a starter system tester.
^ Connect and operate the equipment in accordance with the manufacturer's instructions.
^ Test and troubleshoot as described.
Alternate Procedure:
^ Use following equipment:
- Ammeter, 0 - 400 A
- Voltmeter, 0 - 20 V (accurate within 0.1 volt)
- Tachometer, 0 - 1,200 rpm
Starter Test:
^ Hook up a voltmeter and ammeter as shown.
NOTE: After this test, or any subsequent repair, reset the ECM to clear any codes.
Check the Starter Engagement
Starter Test:
1. Disconnect the 4P connector from the ignition coil.
2. With the shift lever in [P] or [N], turn the ignition switch to START (III).
^ The starter should crank the engine. If the starter does not crank-the engine, go to step 3.
^ If it cranks the engine erratically or too slowly, go to "Check for Wear and Damage" on the next page.
3. Check the battery, battery positive cable, ground, starter cut relay, security control unit, and the wire connections for looseness and corrosion. Test again. If the starter still does not crank the engine, go to step 4.
Starter Test:
4. Unplug the connector (BLK/WHT wire and solenoid terminal) from the starter. Make sure the shift lever is in [P] or [N], then connect a jumper wire from the battery positive (+) terminal to the solenoid terminal. The starter should crank the engine.
^ If the starter still does not crank the engine, remove it, and diagnose its internal problem.
^ If the starter cranks the engine, go to step 5 and continue the test.
5. Check the ignition switch.
6. Check the starter cut relay.
7. Check the A/T gear position switch.
8. Check the security control unit.
9. Check for an open in the BLK/GRN wire between the ignition switch and starter cut relay, and check for an open in the BLK/WHT wire between the starter cut relay and starter.
Check for Wear and Damage
The starter should crank the engine smoothly and steadily. If the starter engages, but cranks the engine erratically, remove it, and inspect the starter drive gear and torque converter ring gear for damage.
Check the drive gear overrunning clutch for binding or slipping when the armature is rotated with the drive gear held. If the clutch is damaged, replace the clutch assembly.
Check Cranking Voltage and Current Draw
Cranking voltage should be no less than 8.5 volts. Current draw should be no more than 380 amperes.
If cranking voltage is too low, or current draw too high, check for:
^ Dead or low battery
^ Open circuit in starter armature commutator segments
^ Starter armature dragging
^ Shorted armature winding
^ Excessive drag in engine
Check Cranking rpm
Engine speed during cranking should be above 100 rpm.
If speed is too low, check for:
^ Loose battery or starter terminals
^ Excessively worn starter brushes
^ Open circuit in commutator segments
^ Dirty or damaged helical spline or drive gear
^ Defective drive gear overrunning clutch
Check Starter Disengagement
With the shift lever in [P] or [N], turn the ignition switch to "START (III)", and release to "ON (II)". The starter drive gear should disengage from the drive plate/ring gear when you release the key.
If the drive gear hangs up on the drive plate/ring gear, check for:
^ Solenoid plunger and switch malfunction
^ Dirty drive gear assembly or damaged overrunning clutch
Starter Solenoid Test
1. Make sure you have the anti-theft code for the radio, then write down the frequencies for the radio's preset buttons.
2. Disconnect the battery negative cable, then disconnect the positive cable.
Starter Solenoid Test:
3. Check the hold-in coil for continuity between the S terminal and the armature housing (ground). The coil is OK if there is continuity.
Starter Solenoid Test:
4. Check the pull-in coil for continuity between the S and M terminals. The coil is OK if there is continuity.
Armature Inspection and Test
Armature Inspection And Test:
1. Inspect the armature for wear or damage due to contact with the permanent magnet. If there is wear or damage, replace the armature.
Armature Inspection And Test:
2. Check commutator surface and diameter.
^ If the surface is dirty or burnt, resurface with emery cloth or a lathe within the following specifications, or recondition with #500 or #600 sandpaper.
^ If commutator diameter is below the service limit, replace the armature.
Armature Inspection And Test:
Commutator Diameter
3. Measure the commutator runout.
^ If the commutator runout is within the service limit, check the commutator for carbon dust or brass chips between the segments.
^ If the commutator runout is not within the service limit, replace the armature.
Armature Inspection And Test:
Commutator Runout
4. Check for mica depth. If necessary, undercut the mica with a hacksaw blade to achieve proper depth. If the service limit cannot be maintained, replace the armature.
Armature Inspection And Test:
Commutator Mica Depth
Armature Inspection And Test:
5. Check for continuity between the segments of the commutator. If an open circuit exists between any segments, replace the armature.
Armature Inspection And Test:
6. Place the armature on an armature tester. Hold a hacksaw blade on the armature core. If the blade is attracted to the core or vibrates while the core is turned, the armature is shorted. Replace the armature.
Armature Inspection And Test:
7. Check with an ohmmeter that no continuity exists between the commutator and armature coil core, and between the commutator and armature shaft. If continuity exists, replace the armature.
Starter Brush Holder Test
Starter Brush Holder Test:
1. Check that there is no continuity between the (+) and (-) brush holders. If there is continuity, replace the brush holder assembly.
Starter Brush Holder Test:
2. Insert the brush into the brush holder, and bring the brush into contact with the commutator, then attach a spring scale to the spring. Measure the spring tension at the moment the spring lifts off the brush.
Spring Tension
15.7 - 17.7 N (1.60 - 1.80 kgf, 3.53 - 3.97 lbf)
Starter Brush Inspection
Measure the brush length. If not within the service limit, replace the brush holder assembly.
Starter Brush Inspection:
Brush Length
NOTE: To seat new brushes after installing them in their holders, slip a strip of #500 or #600 sandpaper, with the grit side up, over the commutator, and smoothly rotate the armature. The contact surface of the brushes will be sanded to the same contour as the commutator.
Overrunning Clutch Inspection
1. Slide the overrunning clutch along the shaft. Does it move freely? If not, replace it.
Overrunning Clutch Inspection:
2. Rotate the overrunning clutch both ways.
Does it lock in one direction and rotate smoothly in reverse? If it does not lock in either direction or it locks in both directions, replace it.
3. If the starter drive gear is worn or damaged, replace the overrunning clutch assembly: the gear is not available separately.
4. C heck the condition of the torque converter ring gear if the starter drive gear teeth are damaged.