Engine Control System Trouble Shooting - No Codes: Other Toyota Sienna I

DOES NOT START

Engine Does Not Crank

1. Check battery and battery cables.
2. Check starter. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
3. Check starter relay. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.

No Initial Combustion

1. Check ECM power source circuit. See ELECTRONIC CONTROL MODULE (ECM) POWER SOURCE CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article.
2. Check engine immobilizer system (if equipped). See appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
3. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.
4. On Land Cruiser, check fuel pump switch. See FUEL DELIVERY under FUEL SYSTEM in SYSTEM & COMPONENT TESTING - V6 & V8 articles.
5. Check Electronic Control Module (ECM) connector for loose, damaged or corroded terminals and repair as necessary. If connector is okay, check ECM ground circuits. See GROUND DISTRIBUTION article in WIRING DIAGRAMS. Repair as necessary. If ground circuits are okay, replace ECM with a known-good ECM and retest.

No Complete Combustion

1. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.

DIFFICULT TO START

Note. On Celica and ECHO, starter signal circuit testing information is not available from manufacturer.

Difficult To Start, Cranks Normal

1. Check starter signal circuit. See STARTER SIGNAL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article.
2. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.
3. Check engine compression. See appropriate BASIC DIAGNOSTIC PROCEDURES article.

Difficult To Start When Cold

1. Check starter signal circuit. See STARTER SIGNAL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article.
2. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.

Difficult To Start When Hot

1. Check starter signal circuit. See STARTER SIGNAL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article.
2. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.

POOR IDLING

High Idle Speed

1. Check A/C compressor signal circuit. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
2. Check ECM power source circuit. See ELECTRONIC CONTROL MODULE (ECM) POWER SOURCE CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article.

Low Idle Speed

1. Check A/C compressor signal circuit. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
2. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.

Rough Idle

1. Check engine compression. See appropriate BASIC DIAGNOSTIC PROCEDURES article.
2. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.

Surging

1. Check ECM power source circuit. See ELECTRONIC CONTROL MODULE (ECM) POWER SOURCE CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article.
2. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.

POOR DRIVEABILITY

Hesitation/Poor Acceleration

1. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.
2. Check for faulty automatic transmission (electronics). See appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS.
3. On Corolla, check A/C cut control circuit. See A/C-CUT CONTROL SYSTEM CIRUCIT under COMPUTERIZED ENGINE CONTROLS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article.

Surging

1. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.

ENGINE STALLS

Engine Stall After Start

1. Check engine immobilizer system. See appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
2. On all models except Camry CNG, Land Cruiser and Tundra V8, check fuel pump control circuit. See FUEL PUMP CONTROL CIRCUIT under COMPUTERIZED ENGINE CONTROLS in appropriate SYSTEM & COMPONENT TESTING article. On Land Cruiser, perform DTC P1200: FUEL PUMP RELAY/ECU CIRCUIT test in SELF-DIAGNOSTICS - LAND CRUISER article. On Camry CNG, check fuel shutoff valve circuit. See DTC P1190: FUEL PRESSURE REGULATOR MALFUNCTION test in SELF-DIAGNOSTICS - CAMRY CNG article. On Tundra V8, check fuel pump control circuit. See DTC P1200: FUEL PUMP RELAY CIRCUIT test in SELF-DIAGNOSTICS - TUNDRA V8 article.

Engine Stall During A/C Operation

1. Check A/C compressor signal circuit. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
2. Check Electronic Control Module (ECM) connector for loose, damaged or corroded terminals and repair as necessary. If connector is okay, check ECM ground circuits. See GROUND DISTRIBUTION article in WIRING DIAGRAMS. Repair as necessary. If ground circuits are okay, replace ECM with a known-good ECM and retest.

REFUELING PROBLEM

Note. This only applies to vehicles equipped with On-Board Refilling Vapor Recovery (ORVR) system.

Unable/Difficult To Refuel

1. Check ORVR system (if equipped). See FUEL EVAP SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
2. Check fuel Evaporation (EVAP) system. See FUEL EVAP SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.

A/C SWITCH INDICATOR BLINKING

Note. Testing procedure for this symptom was only available for Camry 4-cylinder CNG, Camry 4-cylinder gasoline and Camry Solara 4-cylinder models.

1. Check A/C compressor lock sensor circuit. See A/C COMPRESSOR LOCK SENSOR CIRCUIT under COMPUTERIZED ENGINE CONTROLS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article.
2. Check A/C evaporator temperature sensor circuit. See A/C EVAPORATOR TEMPERATURE SENSOR CIRCUIT under COMPUTERIZED ENGINE CONTROLS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article.

Intermittent Simulation

To reproduce the conditions creating an intermittent fault, use the following methods

1. Lightly vibrate component. See «VIBRATION METHOD»(ref-3024-S09311082102000041700000) .
2. Heat component. See «HEATING METHOD»(ref-3024-S37683909542000041700000) .
3. Wiggle or bend wiring harness. See «VIBRATION METHOD»(ref-3024-S09311082102000041700000) .
4. Spray component with water. See «WATER SPRINKLING METHOD»(ref-3024-S11374150432000041700000) .

Monitor circuit/component voltage or resistance while simulating intermittent. If engine is running, monitor for Diagnostic Trouble Codes (DTCs). Use test results to identify a faulty component or circuit.

WATER SPRINKLING METHOD

Spray outside of vehicle and front of radiator with water while checking for a malfunction to occur. DO NOT spray water directly into engine compartment. Temperature and humidity may be changed by spraying water onto front of radiator. DO NOT spray electronic components directly with water.