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Theft Deterrent (Diagnostics): Overview Lexus RX III

Door Locks & Anti-Theft Systems 25 illustrations ~2751 words

DESCRIPTION

The engine hood courtesy switch is installed together with the hood lock. This switch turns on when the engine hood is opened and turns off when the engine hood is closed.

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Scheme 273: WIRING DIAGRAM
Scheme 273: WIRING DIAGRAM

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Scheme 274: PROCEDURE
Scheme 274: PROCEDURE

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  1. READ VALUE USING TECHSTREAM Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Select the item below in the Data List and read the display on the Techstream. MAIN BODY Tester Display Measurement Item/Range Normal Condition Diagnostic Note Hood Courtesy SW Engine hood courtesy switch signal/ON or OFF ON: Engine hood open OFF: Engine hood closed - OK The indicator on the Techstream switches between ON and OFF in accordance with the engine hood courtesy switch status. NG --> See step 2 OK --> See step 6
  2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Disconnect the 2F instrument panel junction block assembly and A main body ECU (multiplex network body ECU) connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 2F-23 - A-20 (HCTY) Always Below 1 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Instrument Panel Junction Block Assembly) *2 Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) NG --> REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY OK: Go to next step
  3. INSPECT HOOD LOCK ASSEMBLY (ENGINE HOOD COURTESY SWITCH) Remove the hood lock assembly. Refer to «REMOVAL»(ref-400879-S19930300752011051800000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Switch Condition Specified Condition A9-1 (E) - A9-2 (+) Unlocked Below 1 ohms Locked 10 kohms or higher TEXT IN ILLUSTRATION *1 Component without harness connected (Hood Lock Assembly (Engine Hood Courtesy Switch)) *2 Unlock *3 Lock NG --> See step 7 OK: Go to next step
  4. CHECK HARNESS AND CONNECTOR (ENGINE HOOD COURTESY SWITCH - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A9-1 (E) - Body ground Always Below 1 ohms TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Hood Lock Assembly (Engine Hood Courtesy Switch)) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  5. CHECK HARNESS AND CONNECTOR (ENGINE HOOD COURTESY SWITCH - MAIN BODY ECU) Reconnect the 2F instrument panel junction block assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A9-2 (+) - A-20 (HCTY) Always Below 1 ohms A9-2 (+) - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Hood Lock Assembly (Engine Hood Courtesy Switch)) *2 Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 8
  6. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to «REMOVAL»(ref-400866-S02233239402011051800000)
  7. REPLACE HOOD LOCK ASSEMBLY (ENGINE HOOD COURTESY SWITCH). Refer to «REMOVAL»(ref-400879-S19930300752011051800000)
  8. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to «REMOVAL»(ref-400866-S02233239402011051800000)

The engine hood courtesy switch is installed together with the hood lock. This switch turns on when the engine hood is opened and turns off when the engine hood is closed.

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (multiplex network body ECU) transmits a signal to cause the horn to sound at intervals of 0.4 seconds.

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Scheme 278: WIRING DIAGRAM
Scheme 278: WIRING DIAGRAM

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Scheme 279: PROCEDURE
Scheme 279: PROCEDURE
  1. INSPECT HORNS Press the horn switch and check if the horns sound. Result Result Proceed to Horns sound A Horns do not sound B B --> See step 4 A: Go to next step
  2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Disconnect the 2F instrument panel junction block assembly and A main body ECU (multiplex network body ECU) connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 2F-24 - A-28 (HORN) Always Below 1 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Instrument Panel Junction Block Assembly) *2 Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) NG --> REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY OK --> See step 3
  3. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to «REMOVAL»(ref-400866-S02233239402011051800000)
  4. GO TO HORN SYSTEM. Refer to «PROBLEM SYMPTOMS TABLE»(ref-400945-S30306371312011051800000)

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (multiplex network body ECU) transmits a signal to cause the horn to sound at intervals of 0.4 seconds.

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (multiplex network body ECU) controls the security horn.

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Scheme 280: WIRING DIAGRAM
Scheme 280: WIRING DIAGRAM

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Scheme 281: PROCEDURE
Scheme 281: PROCEDURE

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  1. PERFORM ACTIVE TEST USING TECHSTREAM Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Select the item below in the Active Test and then check that the security horn assembly operates. BODY Tester Display Test Part Control Range Diagnostic Note Security Horn Security horn ON/OFF - OK The security horn assembly sounds and stops correctly when operated through the Techstream. NG --> See step 2 OK --> See step 8
  2. INSPECT SECURITY HORN ASSEMBLY Remove the security horn assembly. Refer to «REMOVAL»(ref-400879-S32805088872011051800000) . Check the operation of the security horn assembly. OK Measurement Condition Specified Condition Battery positive (+) --> A8-1 (B) Horn sounds Battery negative (-) --> Horn body NG --> See step 9 OK: Go to next step
  3. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Disconnect the 2F instrument panel junction block assembly and A main body ECU (multiplex network body ECU) connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 2F-22 - A-17 (SH) Always Below 1 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Instrument Panel Junction Block Assembly) *2 Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) NG --> REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY OK: Go to next step
  4. CHECK HARNESS AND CONNECTOR (S-HORN RELAY POWER SOURCE) Disconnect the 3A power distributor connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition 3A-1 - Body ground Always 11 to 14 V TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Power Distributor (Engine Room Junction Block Assembly)) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  5. INSPECT POWER DISTRIBUTOR (S-HORN RELAY) Remove the power distributor from the engine room relay block. Connect a positive (+) lead from the battery to terminal 3A-1. Connect a negative (-) lead from the battery to terminal 3C-8. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition 3C-9 - Battery negative Always 11 to 14 V TEXT IN ILLUSTRATION *1 Component without harness connected (Power Distributor (Engine Room Junction Block Assembly)) *2 Component without harness connected (Power Distributor (Engine Room Junction Block Assembly)) NG --> REPLACE POWER DISTRIBUTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY) OK: Go to next step
  6. CHECK HARNESS AND CONNECTOR (POWER DISTRIBUTOR (S-HORN RELAY) - MAIN BODY ECU) Reconnect the 2F instrument panel junction block assembly connector. Measure the resistance on the relay block side according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3C-8 - A-17 (SH) Always Below 1 ohms 3C-8 - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Power Distributor (Engine Room Junction Block Assembly)) *2 Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  7. CHECK HARNESS AND CONNECTOR (SECURITY HORN ASSEMBLY - POWER DISTRIBUTOR (S-HORN RELAY)) Disconnect the A8 security horn assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A8-1 (B) - 3C-9 Always Below 1 ohms 3C-9 - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Security Horn Assembly) *2 Front view of wire harness connector (to Power Distributor (Engine Room Junction Block Assembly)) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 10
  8. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to «REMOVAL»(ref-400866-S02233239402011051800000)
  9. REPLACE SECURITY HORN ASSEMBLY. Refer to «REMOVAL»(ref-400879-S32805088872011051800000)
  10. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to «REMOVAL»(ref-400866-S02233239402011051800000)

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (multiplex network body ECU) controls the security horn.

Even when the theft deterrent system is in the disarmed state, the security indicator light blinks due to a signal output from the immobilizer system. The security indicator light blinks continuously due to a continuous signal received from the immobilizer system while in the armed state.

The main body ECU (multiplex network body ECU) causes the security indicator light to come on only during the arming preparation and alarm sounding states.

Scheme 287

Scheme 287: WIRING DIAGRAM
Scheme 287: WIRING DIAGRAM

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Scheme 288: PROCEDURE
Scheme 288: PROCEDURE

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  1. PERFORM ACTIVE TEST USING TECHSTREAM Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Select the item below in the Active Test and then check that the indicator operates. MAIN BODY Tester Display Test Part Control Range Diagnostic Note Security Indicator Security indicator ON / OFF - OK The security indicator light flashes and goes off correctly when operated through the Techstream. NG --> See step 2 OK --> See step 5
  2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Disconnect the 2D instrument panel junction block assembly and A main body ECU (multiplex network body ECU) connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 2D-35 - A-23 (IND) Always Below 1 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Instrument Panel Junction Block Assembly) *2 Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) NG --> REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY OK: Go to next step
  3. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY (SECURITY INDICATOR) - MAIN BODY ECU) Reconnect the 2D instrument panel junction block assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition G8-7 (LP) - A-23 (IND) Always Below 1 ohms G8-7 (LP) - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Radio Receiver Assembly) *2 Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  4. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY (SECURITY INDICATOR) - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition G8-9 (GND) - Body ground Always Below 1 ohms TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Radio Receiver Assembly) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 6
  5. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-400942-S01837913402011051800000)
  6. REPLACE RADIO RECEIVER ASSEMBLY (SECURITY INDICATOR LIGHT). Refer to «REMOVAL»(ref-400879-S20140153082011051800000)

Even when the theft deterrent system is in the disarmed state, the security indicator light blinks due to a signal output from the immobilizer system. The security indicator light blinks continuously due to a continuous signal received from the immobilizer system while in the armed state.

The main body ECU (multiplex network body ECU) causes the security indicator light to come on only during the arming preparation and alarm sounding states.

When the glass breakage sensor detects that any door glass is tapped or broken, the theft deterrent system switches from the armed state to the alarm sounding state.

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Scheme 291: WIRING DIAGRAM
Scheme 291: WIRING DIAGRAM

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Scheme 292: PROCEDURE
Scheme 292: PROCEDURE

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Scheme 296
  1. INSPECT GLASS BREAKAGE SENSOR WIRE Disconnect the eF2 junction connector and e2 glass breakage sensor ECU connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition e2-2 (GB+B) - eF2-4 (GB+B) Always Below 1 ohms e2-3 (GBIG) - eF2-8 (GBIG) Always Below 1 ohms e2-5 (GBSI) - eF2-2 (GBSI) Always Below 1 ohms e2-6 (GND) - eF2-1 (GND) Always Below 1 ohms e2-7 (MIC-) - eF2-5 (MI-) Always Below 1 ohms e2-8 (MIC+) - eF2-6 (MI+) Always Below 1 ohms eF2-1 (GND) - Body ground Always 10 kohms or higher eF2-2 (GBSI) - Body ground Always 10 kohms or higher eF2-4 (GB+B) - Body ground Always 10 kohms or higher eF2-5 (MI-) - Body ground Always 10 kohms or higher eF2-6 (MI+) - Body ground Always 10 kohms or higher eF2-8 (GBIG) - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Glass Breakage Sensor ECU) *2 Front view of wire harness connector (to Junction Connector) NG --> REPAIR OR REPLACE GLASS BREAKAGE SENSOR WIRE OK: Go to next step
  2. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - POWER SOURCE) Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition eF2-4 (GB+B) - Body ground Always 11 to 14 V eF2-8 (GBIG) - Body ground Engine switch on (IG) 11 to 14 V eF2-8 (GBIG) - Body ground Engine switch off Below 1 V TEXT IN ILLUSTRATION *1 Component without harness connected (Junction Connector) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  3. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition eF2-1 (GND) - Body ground Always Below 1 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Junction Connector) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  4. CHECK HARNESS AND CONNECTOR (GLASS BREAKAGE SENSOR MICROPHONE - JUNCTION CONNECTOR) Disconnect the F25 glass breakage sensor microphone connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F25-7 (MIC+) - eF2-6 (MI+) Always Below 1 ohms F25-8 (MIC-) - eF2-5 (MI-) Always Below 1 ohms F25-7 (MIC+) - Body ground Always 10 kohms or higher F25-8 (MIC-) - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Glass Breakage Sensor Microphone) *2 Component without harness connected (Junction Connector) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  5. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) - J/C) Disconnect the F14 main body ECU (multiplex network body ECU) connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F14-11 (GBS) - eF2-2 (GBSI) Always Below 1 ohms F14-11 (GBS) - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) *2 Component without harness connected (Junction Connector) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
  6. REPLACE GLASS BREAKAGE SENSOR MICROPHONE Replace the glass breakage sensor microphone. Refer to «REMOVAL»(ref-400879-S12658966092011051800000) . NEXT: Go to next step
  7. CHECK GLASS BREAKAGE SENSOR Check the operation of the glass breakage sensor. Refer to «SYSTEM DESCRIPTION»(ref-400942-S05004211892011051800000) . OK When tapping on the glass breakage sensor microphone with your finger, the alarm function operates. NG --> See step 8 OK --> END
  8. REPLACE GLASS BREAKAGE SENSOR ECU Replace the glass breakage sensor ECU. Refer to «REMOVAL»(ref-400879-S41361768832011051800000) . NEXT: Go to next step
  9. CHECK GLASS BREAKAGE SENSOR Check the operation of the glass breakage sensor. Refer to «SYSTEM DESCRIPTION»(ref-400942-S05004211892011051800000) . OK When tapping on the glass breakage sensor microphone with your finger, the alarm function operates. NG --> See step 10 OK --> END
  10. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to «REMOVAL»(ref-400866-S02233239402011051800000)

When the glass breakage sensor detects that any door glass is tapped or broken, the theft deterrent system switches from the armed state to the alarm sounding state.

This circuit provides power for main body ECU (multiplex network body ECU) operation.

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Scheme 297: WIRING DIAGRAM
Scheme 297: WIRING DIAGRAM

This circuit provides power for main body ECU (multiplex network body ECU) operation.

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