2009 Lexus IS FFACTORY OEM SERVICE PROCEDURE

Problem Symptoms Table

WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

HINT: 

When a malfunction is not confirmed by a DTC (Diagnostic Trouble Code) check and the cause of problem cannot be identified through a basic inspection, troubleshoot according to the priority order indicated in the table below.

SFI SYSTEM

Symptom Suspected Area See
w/o Smart Key System: Engine does not crank (Does not start) 1. Immobilizer system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
2. VC output circuit (ECM 5 V output) Refer to VC Output Circuit
3. Starter signal circuit Refer to DTC P0617: Starter Relay Circuit High
4. Starter Refer to INSPECTION
5. ST relay Refer to ON-VEHICLE INSPECTION
6. ECM power source circuit Refer to ECM Power Source Circuit
7. ECM Refer to REMOVAL
w/ Smart Key System: Engine does not crank (Does not start) 1. Smart key system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
2. Immobilizer system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
3. VC output circuit (ECM 5 V output) Refer to VC Output Circuit
4. Cranking holding function circuit Refer to Cranking Holding Function Circuit
6. Starter Refer to INSPECTION
7. ST relay Refer to ON-VEHICLE INSPECTION
8. ECM power source circuit Refer to ECM Power Source Circuit
9. ECM Refer to REMOVAL
No initial combustion (Does not start) 1. ECM power source circuit Refer to ECM Power Source Circuit
2. VC output circuit (ECM 5 V output) Refer to VC Output Circuit
3. Ignition system Refer to ON-VEHICLE INSPECTION
4. Fuel pump control circuit Refer to Fuel Pump Control Circuit
5. Injector Refer to INSPECTION
6. Crankshaft position sensor Refer to INSPECTION
7. ECM Refer to REMOVAL
Engine cranks normally but difficult to start 1. Electronic Throttle Control System (ETCS) Refer to DTC P2102: Throttle Actuator Control Motor Circuit Low; DTC P2103: Throttle Actuator Control Motor Circuit High
2. Fuel pump control circuit Refer to Fuel Pump Control Circuit
3. Ignition system Refer to ON-VEHICLE INSPECTION
4. Spark plug Refer to ON-VEHICLE INSPECTION
5. Compression Refer to ON-VEHICLE INSPECTION - Step 4
6. Injector Refer to INSPECTION
7. Crankshaft position sensor Refer to INSPECTION
Difficult to start with cold engine 1. Starter signal circuit (w/o smart key system) Refer to DTC P0617: Starter Relay Circuit High
2. Cranking holding function circuit (w/ smart key system) Refer to Cranking Holding Function Circuit
3. Electronic Throttle Control System (ETCS) Refer to DTC P2102: Throttle Actuator Control Motor Circuit Low; DTC P2103: Throttle Actuator Control Motor Circuit High
4. Fuel pump control circuit Refer to Fuel Pump Control Circuit
5. Spark plug Refer to ON-VEHICLE INSPECTION
6. Ignition system Refer to ON-VEHICLE INSPECTION
7. Injector Refer to INSPECTION
8. Engine coolant temperature sensor Refer to INSPECTION
Difficult to start with warm engine 1. Starter signal circuit (w/o smart key system) Refer to DTC P0617: Starter Relay Circuit High
2. Cranking holding function circuit (w/ smart key system) Refer to Cranking Holding Function Circuit
3. Electronic Throttle Control System (ETCS) Refer to DTC P2102: Throttle Actuator Control Motor Circuit Low; DTC P2103: Throttle Actuator Control Motor Circuit High
4. Fuel pump control circuit Refer to Fuel Pump Control Circuit
5. Spark plug Refer to ON-VEHICLE INSPECTION
6. Ignition system Refer to ON-VEHICLE INSPECTION
7. Injector Refer to INSPECTION
8. Engine coolant temperature sensor Refer to INSPECTION
High engine idling speed (Poor idling) 1. Electronic Throttle Control System (ETCS) Refer to DTC P2102: Throttle Actuator Control Motor Circuit Low; DTC P2103: Throttle Actuator Control Motor Circuit High
2. ECM power source circuit Refer to ECM Power Source Circuit
3. A/C signal circuit (Compressor circuit) -
4. Acoustic Control Induction System (ACIS) Refer to ACIS Control Circuit
5. PCV hose Refer to ON-VEHICLE INSPECTION
6. ECM Refer to REMOVAL
Low engine idling speed (Poor idling) 1. Electronic Throttle Control System (ETCS) Refer to DTC P2102: Throttle Actuator Control Motor Circuit Low; DTC P2103: Throttle Actuator Control Motor Circuit High
2. ECM power source circuit Refer to ECM Power Source Circuit
3. A/C signal circuit (Compressor circuit) -
4. Acoustic Control Induction System (ACIS) Refer to ACIS Control Circuit
5. PCV hose Refer to ON-VEHICLE INSPECTION
6. Injector Refer to INSPECTION
7. ECM Refer to REMOVAL
Rough idling (Poor idling) 1. Electronic Throttle Control System (ETCS) Refer to DTC P2102: Throttle Actuator Control Motor Circuit Low; DTC P2103: Throttle Actuator Control Motor Circuit High
2. Injector Refer to INSPECTION
3. Ignition system Refer to ON-VEHICLE INSPECTION
4. Compression Refer to ON-VEHICLE INSPECTION - Step 4
5. Fuel pump control circuit Refer to Fuel Pump Control Circuit
6. Spark plug Refer to ON-VEHICLE INSPECTION
7. Acoustic Control Induction System (ACIS) Refer to ACIS Control Circuit
8. PCV hose Refer to ON-VEHICLE INSPECTION
Hunting (Poor idling) 1. Electronic Throttle Control System (ETCS) Refer to DTC P2102: Throttle Actuator Control Motor Circuit Low; DTC P2103: Throttle Actuator Control Motor Circuit High
2. ECM power source circuit Refer to ECM Power Source Circuit
3. Fuel pump control circuit Refer to Fuel Pump Control Circuit
4. Spark plug Refer to ON-VEHICLE INSPECTION
5. Ignition system Refer to ON-VEHICLE INSPECTION
6. Injector Refer to INSPECTION
7. Acoustic Control Induction System (ACIS) Refer to ACIS Control Circuit
8. PCV hose Refer to ON-VEHICLE INSPECTION
Hesitation/Poor acceleration (Poor driveability) 1. Injector Refer to INSPECTION
2. Fuel pump control circuit Refer to Fuel Pump Control Circuit
3. Ignition system Refer to ON-VEHICLE INSPECTION
4. Spark plug Refer to ON-VEHICLE INSPECTION
5. Air Intake Control System (AICS) Refer to Air Intake Control Circuit
6. A/T faulty Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Surging (Poor driveability) 1. Fuel pump control circuit Refer to Fuel Pump Control Circuit
2. Spark plug Refer to ON-VEHICLE INSPECTION
3. Ignition system Refer to ON-VEHICLE INSPECTION
4. Injector Refer to INSPECTION
Engine stalls soon after starting 1. Fuel pump control circuit Refer to Fuel Pump Control Circuit
2. Electronic Throttle Control System (ETCS) Refer to DTC P2102: Throttle Actuator Control Motor Circuit Low; DTC P2103: Throttle Actuator Control Motor Circuit High
3. Crankshaft position sensor Refer to INSPECTION
4. Spark plug Refer to ON-VEHICLE INSPECTION
5. Ignition system Refer to ON-VEHICLE INSPECTION
6. Injector Refer to INSPECTION
Engine stalls during A/C operation 1. A/C signal circuit -
2. ECM Refer to REMOVAL
Unable/difficult to refuel Refueling valve (canister) -
Engine vibrates frequently when idling (Active Control engine Mount (ACM) system does not operate) Active control engine mount circuit Refer to Active Control Engine Mount System
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.

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