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Home >> Lexus >> 2004 >> LX 470 >> Repair and Diagnosis >> Engine Performance >> Engine Control System - Diagnosis >> Circuit Inspection >> Cranking Hold Function Circuit >> Inspection Procedure
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Inspection Procedure

Hand-held tester: 

  1. Check operation of engine cranking. 

    CHECK: 

    When turning the ignition switch to the START position, check whether the starter motor starts.

    OK: 

    1. Starter motor starts. 
    1. OK: Check for intermittent problems (See  PRE-CHECK  ). 
    2. NG: Go to Next Step. 
  2. Connect hand-held tester, and check STA signal. 

    PREPARATION: 

    1. Connect the hand-held tester to the DLC3.
    2. Turn the ignition switch ON, and push the hand-held tester main switch ON.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / STARTER SIG.

    CHECK: 

    Read the STA signal on the hand-held tester while the starter operates.

    OK: 

    Fig 1: STA Signal Reference Chart
    G01428234Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Go to step   5 . 
    2. OK: Go to Next Step. 
  3. Check voltage between terminal STAR, STSW and E1 of ECM connector. 

    CHECK: 

    Measure the voltage between the terminals of the E6 and E7 ECM connectors, while cranking the engine (ignition switch START position).

    Fig 2: Checking Voltage Between Terminal STAR, STSW And E1 Of ECM Connector
    G01428237Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Fig 3: Voltage Reference Chart
    G01428235Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    RESULT: 

    Fig 4: Terminal Reference Chart
    G01428236Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. B: Replace ECM (See  ENGINE CONTROL MODULE (ECM)  ). 
    2. C: Go to step   9 . 
    3. A: Go to Next Step. 
  4. Check park/neutral position switch. 

    PREPARATION: 

    Remove the P1 park/neutral position switch connector.

    Fig 5: Identifying Connector Terminal Of Park/Neutral Position Switch
    G01428239Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Check continuity between each terminal shown below when the shift lever is moved to each range.

    Fig 6: Continuity Reference Chart
    G01428238Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    1. There is continuity. 
    1. NG: Replace the park/neutral position switch. 
    2. OK: Check and repair harness and connector between park/neutral position switch and ECM (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
  5. Check starter relay (See  STARTERS  ). 
    1. NG: Replace starter relay. 
    2. OK: Go to Next Step. 
  6. Check for open and short in harness and connector between park/neutral position switch and starter relay, starter relay and body ground (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    1. NG: Repair or replace harness or connector. 
    2. OK: Go to Next Step 
  7. Check engine room R/B (Starter relay voltage). 

    PREPARATION: 

    Remove the starter relay from the engine room R/B.

    CHECK: 

    Measure the voltage between the terminal of the engine room R/B and body ground.

    Fig 7: Identifying Starter Relay
    G01428241Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Fig 8: Voltage Reference Chart
    G01428240Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Check and repair harness and connector between starter relay and battery. 
    2. OK: Go to Next Step. 
  8. Check starter (See  STARTERS  ). 
    1. NG: Repair or replace starter. 
    2. OK: Go to Next Step 
  9. Check ignition switch. 

    PREPARATION: 

    1. Remove the lower finish panel.
    2. Disconnect the ignition switch connector.
      3. Fig 9: Checking Ignition Switch
      G01428243Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Check continuity between terminals shown below.

    OK: 

    Fig 10: Continuity Reference Chart
    G01428242Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Replace ignition switch. 
    2. OK: Check for open in harness and connector between ECM and ignition switch, ignition switch and battery (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 

OBD II scan tool (excluding hand-held tester): 

  1. Check operation of engine cranking. 

    CHECK: 

    When turning the ignition switch to the ST position, check whether the starter motor starts.

    1. OK: Check for intermittent problems (See  PRE-CHECK  ). 
    2. NG: Go to Next Step. 
  2. Check voltage between terminal STSW, STAR, STA and E1 of ECM connector. 

    CHECK: 

    Measure the voltage between the terminals of E6, E7 and E8 ECM connectors, while cranking the engine (ignition switch START position).

    Fig 11: Checking Voltage Between Terminal STSW, STAR, STA And E1 Of ECM Connector
    G01428245Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Fig 12: Voltage Reference Chart
    G01428244Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    RESULT: 

    Fig 13: Result Table
    G01428246Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. B: Go to step   7 . 
    2. C: Replace ECM (See  ENGINE CONTROL MODULE (ECM)  ). 
    3. D: Go to step   8 . 
    4. A: Go to Next Step. 
  3. Check starter relay (See  STARTERS  ). 
    1. NG: Replace starter relay. 
    2. OK: Go to Next Step. 
  4. Check for open and short in harness and connector between park/neutral position switch and starter relay, starter relay and body ground (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    1. NG: Repair or replace harness or connector. 
    2. OK: Go to Next Step. 
  5. Check engine room R/B (Starter relay voltage). 

    PREPARATION: 

    Remove the starter relay from the engine room R/B.

    Fig 14: Checking Engine Room R/B (Starter Relay Voltage)
    G01428248Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Measure the voltage between the terminal of the engine room R/B and body ground.

    OK: 

    Fig 15: Voltage Reference Chart
    G01428247Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Check and repair harness and connector between starter relay and battery (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    2. OK: Go to Next Step. 
  6. Check starter (See  STARTERS  ). 
    1. NG: Repair or replace starter. 
    2. OK: Check and repair harness and connector between starter relay and starter, starter and battery (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
  7. Check park/neutral position switch. 

    PREPARATION: 

    Remove the P1 park/neutral position switch connector.

    Fig 16: Identifying Terminals Of Park/Neutral Position Switch
    G01428250Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Check continuity between each terminal shown below when the shift lever is moved to each range.

    Fig 17: Continuity Reference Chart
    G01428249Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    1. There is continuity. 
    1. NG: Replace the park/neutral position switch. 
    2. OK: Check and repair harness and connector between park/neutral position switch and ECM (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
  8. Check ignition switch. 

    PREPARATION: 

    1. Remove the lower finish panel.
    2. Disconnect the ignition switch connector.
      3. Fig 18: Checking Ignition Switch
      G01428252Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Check continuity between terminals shown below.

    OK: 

    Fig 19: Continuity Reference Chart
    G01428251Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Replace ignition switch. 
    2. OK: Check and replace harness and connector between ECM and ignition switch, ignition switch and battery (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
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