2004 Toyota Avalon XLSFACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. Check voltage between terminals +B and E1 of ECM connectors. 

    PREPARATION: 

    1. Remove the glove compartment (See ENGINE CONTROL MODULE (ECM) ).
    2. Turn the ignition switch ON.
      Fig 1: Checking Voltage Terminals +B And E1 Of ECM Connectors
      G02835949Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Measure the voltage between terminals +B and E1 of the ECM connectors.

    OK: 

    Voltage: 9 - 14 V 

    1. OK: Proceed to next circuit inspection shown on problem symptoms table (See  PROBLEM SYMPTOMS TABLE  ). 
    2. NG: Go to next step. 
  2. Check for open in harness and connector between terminal E1 of ECM and body ground (See  PROCEDURE  ). 
    1. NG: Repair or replace harness or connector. 
    2. OK: Go to next step. 
  3. Check voltage between terminal IGSW of ECM connector and body ground. 

    PREPARATION: 

    1. Remove the glove compartment (See ENGINE CONTROL MODULE (ECM) ).
    2. Turn the ignition switch ON.
      Fig 2: Measuring Voltage Terminal IGSW Of ECM Connector & Body Ground
      G02835950Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Measure the voltage between terminal IGSW of the ECM connector and body ground.

    OK: 

    Voltage: 9 - 14 V 

    1. OK: Go to Step   5 . 
    2. NG: Go to next step. 
  4. Check AM2 fuse (See  DTC P0351 IGNITION COIL "A" PRIMARY/SECONDARY CIRCUIT, DTC P0352: IGNITION COIL "B" PRIMARY/SECONDARY CIRCUIT, DTC P0353: IGNITION COIL "C" PRIMARY/SECONDARY CIRCUIT, DTC P0354: IGNITION COIL "D" PRIMARY/SECONDARY CIRCUIT, DTC P0355: IGNITION COIL "E" PRIMARY/SECONDARY CIRCUIT, DTC P0356: IGNITION COIL "F" PRIMARY/SECONDARY CIRCUIT  . 
    1. NG: Check for short in all harness and components connected to AM2 fuse. 
    2. OK: Go to next step. 
  5. Check ignition switch (See  INSPECTION  ).  
    1. NG: Replace ignition switch. 
    2. OK: Check and repair harness and connector between battery and ignition switch, and ignition switch and ECM. 
  6. Check voltage between terminal MREL of ECM connector and body ground. 

    PREPARATION: 

    1. Remove the glove compartment (See ENGINE CONTROL MODULE (ECM) ).
    2. Turn the ignition switch ON.
      Fig 3: Measuring Voltage Terminal MREL ECM Connector & Body Ground
      G02835951Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    CHECK: 

    Measure the voltage between terminal MREL of the ECM connector and body ground.

    OK: 

    Voltage: 9 - 14V 

    1. NG: Check and replace ECM (See  PROCEDURE  ). 
    2. OK: Go to next step. 
  7. Check EFI No.1 fuse (See  DTC P0560 SYSTEM VOLTAGE  , step 2). 
    1. NG: Check for short in all harness and components connected to EFI No.1 fuse. 
    2. OK: Go to next step. 
  8. Check EFI No.2 fuse. 

    PREPARATION: 

    Remove the EFI No.2 fuse from the engine room J/B.

    CHECK: 

    Check the continuity of the EFI No.2 fuse.

    Fig 4: Identifying Location Of EFI No. 2 fuse In Engine Room J/B
    G02835952Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    Continuity 

    1. NG: Check for short in all harness and components connected to EFI No.2 fuse. 
    2. OK: Go to next step. 
  9. Check EFI main relay (Marking: EFI) (See  EFI MAIN RELAY  ).  
    1. NG: Replace EFI main relay. 
    2. OK: Go to next step. 
  10. Check for open and short in harness and connector between terminal MREL of ECM and body ground (See  PROCEDURE  ). 
    1. NG: Repair or replace harness or connector. 
    2. OK: Check and repair harness or connector between EFI No.1 fuse and battery. 
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.