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Problem Symptoms Table

WARNING: This page is about a different car, the 2009 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.

HINT: 

Use the table below to help determine the cause of the problem. The potential cases of the symptoms are listed in order of probability in the "Suspected area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

SFI SYSTEM

Symptom Suspected Area See
Engine does not crank (Does not start) 1. Check push-start function initialization Refer to INITIALIZATION
2. Immobilizer System Refer to PROBLEM SYMPTOMS TABLE
3. ECM power source circuit Refer to ECM Power Source Circuit
4. VC output circuit Refer to VC Output Circuit
5. Cranking holding function circuit Refer to Cranking Holding Function Circuit
6. Starter Refer to INSPECTION
No initial combustion (Does not start) 1. ECM power source circuit Refer to ECM Power Source Circuit
2. Fuel pump control circuit Refer to Fuel Pump Control Circuit
3. ECM Refer to TERMINALS OF ECM 
Engine cranks normally but difficult to start 1. Fuel pump control circuit Refer to Fuel Pump Control Circuit
2. Compression Refer to ON-VEHICLE INSPECTION - Step 9
Difficult to start with cold engine 1. Cranking holding function circuit Refer to Cranking Holding Function Circuit
2. Ignition system Refer to ON-VEHICLE INSPECTION
3. Spark plug Refer to ON-VEHICLE INSPECTION - Step 2
4. Fuel pump control circuit Refer to Fuel Pump Control Circuit
5. Injector Refer to INSPECTION
Difficult to start with worm engine 1. Cranking holding function circuit Refer to Cranking Holding Function Circuit
2. Injector Refer to INSPECTION
3. Ignition system Refer to ON-VEHICLE INSPECTION
4. Spark plug Refer to ON-VEHICLE INSPECTION - Step 2
5. Fuel pump control circuit Refer to Fuel Pump Control Circuit
High engine idle speed (Poor idling) 1. ECM power source circuit Refer to ECM Power Source Circuit
2. A/C signal circuit (compressor circuit) -
3. Electronic throttle control system Refer to ON-VEHICLE INSPECTION
4. Air induction system -
5. PCV hose -
Low engine idle speed (Poor idling) 1. A/C signal circuit (compressor circuit) -
2. Fuel pump control circuit Refer to Fuel Pump Control Circuit
3. Electronic throttle control system Refer to ON-VEHICLE INSPECTION
4. Air induction system -
5. PCV hose -
Rough idling (Poor idling) 1. Compression Refer to ON-VEHICLE INSPECTION - Step 9
2. Fuel pump control circuit Refer to Fuel Pump Control Circuit
3. Electronic throttle control system Refer to ON-VEHICLE INSPECTION
4. Air induction system -
5. PCV hose -
Hunting (Poor idling) 1. ECM power source circuit Refer to ECM Power Source Circuit
2. Fuel pump control circuit Refer to Fuel Pump Control Circuit
3. Spark plug Refer to ON-VEHICLE INSPECTION - Step 2
4. Ignition system Refer to ON-VEHICLE INSPECTION
5. Injector Refer to INSPECTION
6. Electronic throttle control system Refer to ON-VEHICLE INSPECTION
7. Air induction system -
8. PCV hose -
Hesitation/ Poor acceleration (Poor driveability) 1. Fuel pump control circuit Refer to Fuel Pump Control Circuit
2. Spark plug Refer to ON-VEHICLE INSPECTION - Step 2
3. Ignition system Refer to ON-VEHICLE INSPECTION
4. Injector Refer to INSPECTION
Surging (Poor driveability) 1. Spark plug Refer to ON-VEHICLE INSPECTION - Step 1
2. Fuel pump control circuit Refer to Fuel Pump Control Circuit
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. Spark plug Refer to ON-VEHICLE INSPECTION - Step 2
3. Ignition system Refer to ON-VEHICLE INSPECTION
4. Injector Refer to INSPECTION
5. Vacuum sensor circuit -
Engine stalls during A/C operation 1. A/C signal circuit (Compressor circuit) -
2. ECM Refer to TERMINALS OF ECM 
3. Cold start injector Refer to INSPECTION
Unable/difficult refuel Refueling valve (canister) -