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Engine Does Not Crank, Cranks Too Fast/Slow

NOTE: Do not begin this test without a fully charged and sound battery. During cranking with the engine disabled, observe the engine cranking speed. A cranking speed as low as 90 RPM is acceptable, but will be difficult to measure. A degree of discretion must be used as to when an engine is cranking too slowly.
NOTE: For circuit identification, see WIRING DIAGRAMS .
NOTE: For battery reconnect procedure, see BATTERY RECONNECT PROCEDURE  under MISCELLANEOUS.
  1. Check Power Supply, Ground & Trigger To Starter Circuit  - Measure voltage drop across the circuit between the battery positive terminal and the starter motor battery cable terminal. Is voltage drop greater than 1 volt? If yes, check battery connection, cable connections at false bulkhead stud connector, and starter motor connection. Make sure all connections are in good condition and secure. If all connections are okay, install a NEW battery cable and retest system for normal operation. If no, go to next step.
  2. Check Volt Drop Across Starter Circuit  - Disable the fuel or ignition system to prevent the engine starting. Turn the ignition switch to the CRANK position. Measure voltage drop across the circuit between the battery positive terminal and the starter motor battery cable terminal. Is voltage drop greater than 1 volt? If yes, check battery connection, cable connections at false bulkhead stud connector, and starter motor connection. Make sure all connections are in good condition and secure. If all connections are okay, install a NEW battery cable and retest system for normal operation. If no, go to next step.
  3. Check Ground To Starter Motor  - Measure resistance between the engine ground lead and starter motor body. Is the resistance greater than 5 ohms? If yes, clean connection between the starter motor body and the engine block and retest system for normal operation. If no, go to next step.
  4. Check Starter Signal From Starter Relay  - Disconnect starter motor harness connector ST03. Turn the ignition switch to the CRANK position. Measure voltage between starter motor harness connector ST03 and GROUND. Is voltage less than 10 volts? If yes, go to next step. If no, install a NEW starter motor. See STARTER  under REMOVAL & INSTALLATION.
  5. Check Starter Signal Circuit For High Resistance  - Remove starter relay. Measure resistance between starter relay base terminal No. 5 and starter motor harness connector ST03. Is resistance greater than 5 ohms? If yes, repair high resistance between starter relay base terminal No. 5 and starter motor harness connector ST03 and retest system for normal operation. If no, check if DTC(s) P1245 and/or P1246 are set. See SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
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