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Home >> Toyota >> 2004 >> MR2 C65M >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Diagnostics >> DTC P0504: Brake Switch "A'V'B" Correlation* >> Inspection Procedure
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Inspection Procedure

HINT:

Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, as well as other data from the time when a malfunction occurred.

Hand-held tester: 

  1. Check operation of stop light. 

    CHECK: 

    Check if the stop lamps turn ON and OFF normally when the brake pedal is depressed and released.

    1. NG : Check and repair stop light circuit. 
    2. OK : Go To Next Step 
  2. Inspect STOP fuse. 

    PREPARATION: 

    Remove the STOP fuse from the R/B No. 3 and J/B No. 3.

    CHECK: 

    Measure the resistance of the STOP fuse.

    OK: 

    1. Below Ω 
    Fig 1: Measaing Resistance Of Stop Fuse
    G02913847Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG : Check for short in all harness and components connected to STOP fuse. 
    2. OK : Go To Next Step 
  3. Check stop light switch (See  INSPECTION  ). 
    1. NG : Replace stop light switch. 
    2. OK : Go To Next Step 
  4. Check STP signal and ST1-voltage. 

    PREPARATION: 

    1. Turn the ignition switch ON.
    2. Enter the following menus: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/STOP LIGHT SW.

    CHECK: 

    Read the value displayed on the hand-held tester.

    OK: 

    Brake Pedal Specified Condition Table

    Brake Pedal Specified Condition
    Depressed STP Signal ON
    Released STP Signal OFF

    CHECK: 

    Measure the voltage between terminals ST1-and E1 ECM connectors.

    OK: 

    Tester Connection Specified Condition Table

    Tester Connection Brake Pedal Specified Condition
    ST1-(E8-12)-E1(E7-1) Depressed Below 1.5 V
    ST1-(E8-12)-E1(E7-1) Released 7.5 to 14 V
    Fig 2: Measunign Voltage Between Terminals ST1 & E1 ECM Connector
    G02913848Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK : Check for intermittent problems (See  PRE-CHECK  ). 
    2. NG : Go To Next Step. 
  5. Check harness and connector between ECM and stop light switch. 

    PREPARATION: 

    1. Disconnect the stop light switch connector.
    2. Disconnect the ECM connector.

    CHECK: 

    Measure the resistance between the wire harness side connectors.

    OK: 

    Light Switch Connector Terminals Specified Condition Table

    Tester Connection Specified Condition
    Stop light switch (S7-1)-STP (E8-19) Below 1Ω
    Stop light switch (S7-4)-ST1-(E8-12) Below 1Ω
    Stop lught switch (S7-1) or STP (E8-19)-Body ground 10 kΩ or higher
    Stop light switch (S7-4) or ST1-(E8-12)-Body ground 10 kΩ or higher
    Fig 3: Indentifying Stop Light Switch Connector Terminals
    G02913849Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG : Repair or replace harness and connector. 
    2. OK : Replace ECM (See  ENGINE CONTROL MODULE (ECM)  ). 

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

  1. Check operation of stop light. 

    CHECK: 

    Check if the stop lights turn ON and OFF normally when the brake pedal is depressed and released.

    1. NG : Check and repair stop light circuit. 
    2. OK : Go To Next Step 
  2. Inspect STOP fuse. 

    PREPARATION: 

    Remove the STOP fuse from the R/B No. 3 and J/B No. 3.

    CHECK: 

    Measure the resistance of the STOP fuse.

    OK: 

    1. Below 1Ω 
    Fig 4: Identifying Stop Fuse Of R/B No. 3 & J/B.3
    G02913850Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG : Check for short in all harness and components connected to STOP fuse. 
    2. OK : Go To Next Step 
  3. Check stop light switch (See  INSPECTION  ). 
    1. NG : Replace stop light switch. 
    2. OK : Go To Next Step 
  4. Check STP signal. 

    PREPARATION: 

    Turn the ignition switch ON.

    CHECK: 

    Measure the voltage between the specified terminals of the ECM connectors.

    OK: 

    Brake *** specified condition table

    Tester connection Brake Pedal Position Specified Condition
    STP (E8-19)-E1 (E7-1) Depressed 7.5 to 14 V
      Released Below 1.5 V
    ST1-(E8-12)- E1 (E7-1) Depressed Below 1.5 V
      Released 7.5 to 14 V
    Fig 5: Identifying ECM Connector Terminals
    G02913851Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK : Check for intermittent problems (See  PRE-CHECK  ). 
    2. NG : Go To Next Step. 
  5. Check harness and connector between ECM and stop light switch. 

    PREPARATION: 

    1. Disconnect the stop light switch connector.
    2. Disconnect the ECM connector.

    CHECK: 

    Measure the resistance between the wire harness side connectors.

    OK: 

    Tester connection specified condition table.

    Tester Connection Specified Condition
    Stop light switch (S5-1)-STP (E8-19) Below 1Ω
    Stop light switch (S5-4)-ST1-(E8-12) Below 1Ω
    Stop light switch (S5-1) or STP (E8-19)-Body ground 10 kΩ or higher
    Stop light switch (S5-4) or ST1-(E8-12)-Body ground 10 kΩ or higher
    Fig 6: Indentifying Stop Light Switch Connector Terminals
    G02913852Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG : Repair or replace harness and connector. 
    2. OK : Replace ECM (See  ENGINE CONTROL MODULE (ECM)  ). 
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