Automatic A/c-Heater Systems: Other Toyota Prius I рестайлинг

SYSTEM CONTROLS

A/C-heater control assembly is used to activate A/C-heater system, set desired temperature, direct discharged air to appropriate outlets, activate rear defogger, control fan speed and check outside air temperature.

SERVICE PRECAUTIONS

The following service precautions must be followed

Scheme 17

1. Ensure ignition is off and ignition key is removed from ignition before performing any inspection or service procedure in engine compartment, as engine may automatically start and shut off when ignition is on and READY light is illuminated. READY light is displayed just above the shift lever position indicator on instrument cluster at center of instrument panel.
2. Read all service and warning labels in engine compartment before performing any procedures in engine compartment.
3. All high-voltage wire harness connectors contain Orange connectors. DO NOT touch any wiring harness that contains Orange connectors.
4. High-voltage battery and other high-voltage components may be identified by HIGH VOLTAGE caution labels on them. DO NOT touch these components.
5. If necessary to inspect or service high-voltage system, ensure ignition is off. Remove service plug and wait at least 5 minutes to ensure high voltage is fully discharged before touching any high-voltage wiring harness, connectors or components. Service plug is located on service plug assembly at driver's side front corner of trunk compartment, near high-voltage battery. (Scheme 17) Ensure service plug is stored in a location in which no one may install service plug while technician is working on the vehicle.
6. If necessary to touch any high-voltage wiring harness, connectors or components, ensure service plug is removed and battery voltage or less exists at electrical connector. Use Toyota insulated gloves when touching any high-voltage wiring harness, connectors or components. Ensure insulated gloves are dry and in good condition and that no holes exist in insulated gloves by applying air to insulated glove before touching any high-voltage wiring harness, connectors or components.
7. DO NOT wear any metal objects while working on vehicle which may accidently drop and cause a short circuit.
8. If any high-voltage wiring harness connector is disconnected, ensure terminal on wiring harness connector is wrapped with tape to prevent wiring harness connector from contacting any surface.
9. If servicing high-voltage system, place sign on roof of vehicle to indicate to other technicians that high-voltage system is being serviced.

Indicator Check

Within 5 minutes after turning ignition on, press A/C switch 3 times and turn blower switch from OFF to AUTO. Indicators should illuminate, then go off at one second intervals, 4 times in succession. After indicator check, system enters DTC check. See DTC CHECK (SENSOR CHECK) .

Actuator Check Mode

Actuator mode is started at same time as DTC check. Visually or by hand check that airflow, amount of damper operating and operation of compressor changes according to set temperature of A/C control panel. (Scheme 18)

Scheme 18

CODE 11: ROOM TEMPERATURE SENSOR CIRCUIT

1. Remove A/C control assembly, leaving harness connectors connected. See «A/C CONTROL ASSEMBLY»(ref-98934-S41360912392001072500000) under REMOVAL & INSTALLATION. Turn ignition on. Backprobe between connector A9 terminals No. 3 (White wire) and No. 4 (White wire) at A/C control assembly harness connector. (Scheme 19) At 77°F (25°C), about 1.8-2.2 volts should be present. At 104°F (40°C), about 1.2-1.6 volts should be present. If voltages are to specification, room temperature sensor circuit is okay. If voltages are not to specification, go to next step.
2. Remove room temperature sensor. Measure resistance between room temperature sensor connector terminals. See «ROOM TEMPERATURE SENSOR»(ref-98934-S20489807062001072000000) under COMPONENT TESTS. If resistances are not to specification, replace room temperature sensor. If resistances are to specification, check wiring between A/C control assembly and room temperature sensor. See «WIRING DIAGRAMS»(ref-98934-S03455350802001070200000). Repair wiring as necessary. If wiring is okay, replace A/C control assembly.

Scheme 19

SYSTEM TESTS

A/C SYSTEM PERFORMANCE

Park vehicle out of direct sunlight. Ensure inlet air temperature is between 86-95°F (30-35°C). Install manifold gauge set and turn A/C controls to recirculated air position. Start engine and allow to run at 1500 RPM. Set blower/fan on high speed and temperature controls for maximum cooling. Verify high-side and low-side pressures are within specification. See SPECIFICATIONS table.

A7-1 & A7-7

Battery voltage should exist with ignition on.

A7-3 & A7-7

With ignition and blower motor on, a pulse should be generated.

A7-4 & A7-7

With ignition on, a pulse should be generated.

A7-7 & Ground

Continuity at all times.

A7-8 & A7-7

Battery voltage at all times.

A8-10 & A7-7

With ignition, headlights and rear defogger on, and temperature set to maximum hot, battery voltage should be present. With ignition on, headlights and rear defogger off, less than one volt should be present.

A7-11 & A7-7

With ignition on, a pulse should be generated.

A8-1 & A7-7

Start engine. With coolant temperature less than 194°F (90°C) and refrigerant pressure sensor reading less than 220 psi (1520 kPa), battery voltage should be present. With coolant temperature greater than 194°F (90°C) and refrigerant pressure sensor reading greater than 220 psi (1520 kPa), less than one volt should be present.

A8-2 & A7-7

With A/C compressor on, less than one volt should be present. With A/C compressor off, battery voltage should be present.

A8-3 & A7-7

With engine speed greater than 500 RPM and blower on, less than one volt should be present. With engine speed greater than 500 RPM and blower off, battery voltage should be present.

A8-4 & A7-7

With engine started, a pulse should be generated.

A8-5 & A7-7

With engine at idle, battery voltage should be present.

A8-6 & A7-7

Start engine. Turn headlights and defogger off. Set temperature to maximum warm and blower knob on HI. Place mode knob to foot/defrost mode. Witch coolant temperature less than 130°F (55°C), less than .7 volts should be present.

A8-9 & A7-18

Start engine. With A/C compressor on, a pulse should be generated.

A8-11 & A7-7

Start engine. With A/C compressor on, less than one volt should be present. With compressor off, battery voltage should be present.

A8-12 & A7-7

With A/C pressure less than 2.0 kg/cm 2 , battery voltage should be present. With A/C pressure greater than 3.14 kg/cm 2 , less than one volt should be present.

A8-13 & A7-7

Start engine. Turn headlights and rear defogger off. Set temperature to maximum warm and blower knob on HI. Place mode knob to foot/defrost mode. With coolant temperature at 130-157°F (55-70°C), voltage should be less than .7 volts.

A8-18 & A7-7

Continuity should be present at all times.

A9-1 & A9-2

With ignition on and ambient temperature at 77°F (25°C), 1.35-1.75 volts should be present. With ignition on and ambient temperature at 104°F (40°C), .85-1.25 volts should be present.

A9-2 & A7-7

Continuity should be present at all times.

A9-3 & A7-7

Continuity should be present at all times.

A9-4 & A9-3

With ignition on and ambient temperature at 77°F (25°C), 1.8-2.2 volts should be present. With ignition on and ambient temperature at 104°F (40°C), 1.2-1.6 volts should be present.

A9-5 & A9-6

With ignition on and solar sensor subjected to light, less than 4 volts should be present. With ignition on and solar sensor covered, 4-4.5 volts should be present.

A9-6 & A7-7

With ignition on, 4.5-5.5 volts should be present.

A9-7 & A9-9

With ignition on, 4.5-5.5 volts should be present.

A9-8 & A9-9

With ignition on and mode knob on face (vent) mode, less than one volt should be present. With ignition on and mode knob on defrost mode, 4.5-5.5 volts should be present.

A9-9 & A7-7

Continuity should be present at all times.

A9-10 & A7-7

With ignition on and mode knob on face (vent) mode, battery voltage should be present. With ignition on and mode knob on defrost mode, less than one volt should be present.

A9-11 & A7-7

With ignition on and mode knob on face (vent) mode, less than one volt should be present. With ignition on and mode knob on defrost mode, battery voltage should be present.

A9-13 & A7-7

With ignition on and temperature set at maximum cool, battery voltage should be present. With ignition on and temperature set at maximum warm, less than one volt should be present.

A9-14 & A7-7

With ignition on and temperature set at maximum cool, less than one volt should be present. With ignition on and temperature set at maximum warm, battery voltage should be present.

A9-15 & A7-7

Continuity should be present at all times.

A9-16 & A9-15

With ignition on and temperature set to maximum cool, less than one volt should be present. With ignition on and temperature set to maximum warm, 4.5-5.5 volts should be present.

A9-17 & A9-15

With ignition on, 4.5-5.5 volts should be present.

A9-18 & A9-20

With ignition on, 4.5-5.5 volts should be present.

A9-19 & A9-20

With ignition on and air intake selector in fresh air position, less than one volt should be present. With ignition on and air intake selector in recirculated air position, 4.5-5.5 volts should be present.

A9-20 & A7-7

Continuity should be present at all times.

A9-21 & A7-7

With ignition on and air intake selector in fresh air position, less than one volt should be present. With ignition on and air intake selector in recirculated air position, battery voltage should be present.

A9-22 & A7-7

With ignition on and air intake selector in fresh air position, battery voltage should be present. With ignition on and air intake selector in recirculated air position, less than one volt should be present.

BACK-UP POWER SOURCE CIRCUIT

1. Remove A/C control assembly, leaving harness connectors connected. See «A/C CONTROL ASSEMBLY»(ref-98934-S41360912392001072500000) under REMOVAL & INSTALLATION. Turn ignition on. Measure voltage between connector A7 terminal No. 8 (Red/Green wire) and ground. If battery voltage is present, back-up power source circuit is okay. If battery voltage is not present, go to next step.
2. Remove ECU-B (7.5-amp) fuse from instrument panel junction block. Check ECU-B fuse. Replace fuse as necessary. If fuse is okay, repair wiring between A/C-heater control assembly and battery. See «WIRING DIAGRAMS»(ref-98934-S03455350802001070200000) .

BLOWER MOTOR CIRCUIT

Turn ignition off. Remove blower motor. See BLOWER UNIT under REMOVAL & INSTALLATION. Apply battery voltage to motor. If blower motor runs, go to next step. Replace blower motor if it does not run. Check wiring between blower motor and battery, and between blower motor and ground. Repair wiring as necessary. If wiring is okay, check wiring between blower motor linear controller and A/C-heater controller. See WIRING DIAGRAMS . Repair wiring as necessary.

COMPRESSOR CIRCUIT

1. Remove A/C control assembly, leaving harness connectors connected. See «A/C CONTROL ASSEMBLY»(ref-98934-S41360912392001072500000) under REMOVAL & INSTALLATION. Start engine. Push AUTO switch. Measure voltage between connector A8 terminal No. 10 (Light Green/Red wire) and ground. If less than .7 volts are present with switch on, and battery voltage is present with switch off, go to step 4 . If voltage is not to specification, go to next step.
2. Remove clutch relay from engine room junction block. Check relay. See «RELAYS»(ref-98934-S25990201652001072000000) under component tests. Replace relay as necessary. If relay is okay, go to next step.
3. Disconnect compressor clutch 4-pin connector. Connect battery voltage to connector terminal No. 1 (Black/Blue wire). Connect negative terminal to ground. If clutch does not operate, replace clutch. If clutch operates, repair wiring between compressor clutch, relay and A/C control assembly.
4. With ignition on, measure voltage between A/C control assembly connector A8 terminal No. 5 and ground. If battery voltage is present, go to next step. If battery voltage is not present, replace engine ECM located behind right kick panel. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
5. Start engine. Push AUTO button. Measure voltage between connector A8 terminal No. 10 and ground. With clutch activated, battery voltage should be present. With clutch not activated, less than one volt should be present. If voltages are to specification, check wiring between clutch relay and A/C control assembly. If voltages are not to specification, replace A/C control assembly.

CONVERTER CIRCUIT

1. Remove A/C control assembly, leaving harness connectors connected. See «A/C CONTROL ASSEMBLY»(ref-98934-S41360912392001072500000) under REMOVAL & INSTALLATION. Turn ignition on. Turn light control and defogger switches off. Measure voltage between connector A7 terminal No. 10 (Yellow wire) and ground. If less than one volt is present, converter circuit is okay. If greater than one volt is present, go to next step.
2. Turn ignition off. Disconnect connector A7 from A/C control assembly. Turn ignition on. Turn light control and rear defogger switch off. Measure voltage between connector A7 terminal No. 10 (Yellow wire) and ground. If less than one volt is present, replace A/C control assembly. If greater than one volt is present, go to next step.
3. Check wiring and connectors between A/C control assembly and converter. See «WIRING DIAGRAMS»(ref-98934-S03455350802001070200000) . Repair wiring as necessary. If wiring is okay, replace converter. See «WATER PUMP»(ref-98934-S15768995192001072500000) under REMOVAL & INSTALLATION.

HEATER MAIN RELAY CIRCUIT

Remove heater main relay from engine room junction block. Check relay. See RELAYS under COMPONENT TESTS. Replace relay as necessary. If relay is okay, check HTR (30-amp) fuse in engine compartment junction block. Replace HTR fuse as necessary. If HTR fuse is okay, repair wiring between heater main relay and ground, and between heater main relay and body ECU. If wiring is okay, check multiplex control system. See appropriate MULTIPLEX CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT.

IGNITION POWER & GROUND CIRCUITS

1. Remove A/C control assembly, leaving harness connectors connected. See «A/C CONTROL ASSEMBLY»(ref-98934-S41360912392001072500000) under REMOVAL & INSTALLATION. Turn ignition on. Measure voltage between connector A7 terminals No. 7 (White/Black wire) and No. 1 (Red wire). If battery voltage is present, power circuit is okay. If battery voltage is not present, go to next step.
2. Turn ignition off. Check continuity between connector A7 terminal No. 7 (White/Black wire) and ground. If continuity is present, go to next step. If continuity is not present, repair open ground circuit. See «WIRING DIAGRAMS»(ref-98934-S03455350802001070200000) .
3. Remove HTR (30-amp) fuse from instrument panel junction block. Check HTR fuse. Replace fuse as necessary. If fuse is okay, repair wiring between A/C-heater control assembly and battery. See «WIRING DIAGRAMS»(ref-98934-S03455350802001070200000) .

Heater Core Circuit

1. Check converter circuit. See «CONVERTER CIRCUIT»(ref-98934-S06926882062001072500000) . Remove A/C control assembly, leaving harness connectors connected. See «A/C CONTROL ASSEMBLY»(ref-98934-S41360912392001072500000) under REMOVAL & INSTALLATION. Start engine. Set temperature control knob to maximum heat position and blower knob to HI. Turn light control and defogger switches off. Check voltage between connector A8 terminal No. 6 (Pink/Black wire) and ground with airflow selector in specified mode. See «PTC HEATER CIRCUIT (HEATER CORE) CHECK»(ref-98934-S40176293452001072500000) table. If voltages are to specification, go to step 5 . If voltages are not to specification, go to next step.
2. Check HTR1 and HTR2 (30-amp) fuses. Replace fuses as necessary and check for short circuit. See «WIRING DIAGRAMS»(ref-98934-S03455350802001070200000) . If fuses are okay, go to next step.
3. Check heater No. 1 and 2 relays. See «RELAYS»(ref-98934-S25990201652001072000000) under COMPONENT TESTS. Replace relays as necessary. If relays are okay, go to next step.
4. Check wiring and connectors between A/C control assembly and HTR3 (50-amp) fuse. Repair or replace wiring as necessary. If wiring is okay, replace A/C control assembly.
5. Remove heater core. See «HEATER CORE»(ref-98934-S10581858472001070200000) under REMOVAL & INSTALLATION. Check continuity between 2-pin PTC heater connector terminals. If continuity is present, check wiring between PTC heater and heater relay No. 3, and between PTC heater and ground. If continuity is not present, replace heater core.

PTC HEATER CIRCUIT (HEATER CORE) CHECK

Quick Heater Circuit

1. Check converter circuit. See «CONVERTER CIRCUIT»(ref-98934-S06926882062001072500000) . Remove A/C control assembly, leaving harness connectors connected. See «A/C CONTROL ASSEMBLY»(ref-98934-S41360912392001072500000) under REMOVAL & INSTALLATION. Start engine. Set temperature control knob to maximum heat position and blower knob to HI. Turn light control and defogger switches off. Check voltage between connector A8 terminal No. 13 (Pink wire) and ground with airflow selector in specified mode. See «PTC HEATER CIRCUIT (QUICK HEATER) CHECK»(ref-98934-S03986618762001072500000) table. If voltages are to specification, go to step 5 . If voltages are not to specification, go to next step.
2. Check HTR1, HTR2 (30-amp) and HTR3 (50-amp) fuses. Replace fuses as necessary and check for short circuit. See «WIRING DIAGRAMS»(ref-98934-S03455350802001070200000) . If fuses are okay, go to next step.
3. Check heater relays. See «RELAYS»(ref-98934-S25990201652001072000000) under COMPONENT TESTS. Replace relays as necessary. If relays are okay, go to next step.
4. Check wiring and connectors between A/C control assembly and HTR1 and HTR2 (30-amp) fuses. Repair or replace wiring as necessary. If wiring is okay, replace A/C control assembly.
5. Check PTC heater. See «POSITIVE TEMPERATURE COEFFICIENT (PTC) HEATER»(ref-98934-S14153518662001072500000) under COMPONENT TESTS.

PTC HEATER CIRCUIT (QUICK HEATER) CHECK

WATER PUMP CIRCUIT

1. Remove A/C control assembly, leaving harness connectors connected. See «A/C CONTROL ASSEMBLY»(ref-98934-S41360912392001072500000) under REMOVAL & INSTALLATION. Turn ignition on. Operate blower motor. Measure voltage between connector A9 terminal No. 3 (Blue/Red wire) and ground. With engine running, battery voltage should be present. With engine off, less than one volt should be present. If voltages are to specification, circuit is okay. If voltages are not to specification, go to next step.
2. Check A/C water pump relay. See «RELAYS»(ref-98934-S25990201652001072000000) under COMPONENT TESTS. Replace relay as necessary. If relay is okay, go to next step.
3. Remove water pump. See «WATER PUMP»(ref-98934-S15768995192001072500000) under REMOVAL & INSTALLATION. For 10 seconds maximum, connect positive lead from 6 1.5-volt dry cell batteries to water pump connector terminal No. 1, and negative lead to terminal No. 2. If motor operates smoothly, go to next step. If motor does not operate smoothly, replace water pump.
4. Check wiring and connectors between water pump motor and A/C control assembly, and between A/C control assembly and ground. See «WIRING DIAGRAMS»(ref-98934-S03455350802001070200000) . Repair wiring as necessary. If wiring is okay, replace A/C control assembly.

AIR INLET SERVOMOTOR

Apply positive battery voltage to connector terminal No. 4 and negative voltage to terminal No. 5. Lever should move smoothly toward fresh air (FRS) position. Reverse leads. Lever should move smoothly toward recirculated air (REC) position. (Scheme 20) Replace servomotor as necessary.

Scheme 20

AIR MIX SERVOMOTOR

Remove air mix servomotor. See BLOWER UNIT under REMOVAL & INSTALLATION. Disconnect air mix servomotor connector. Apply positive battery voltage to connector terminal No. 4 and negative voltage to terminal No. 5. (Scheme 21) Lever should move smoothly toward cool side. Reverse leads. Lever should move smoothly toward warm side. Replace servomotor as necessary.

Scheme 21

AIR OUTLET SERVOMOTOR

Disconnect air outlet servomotor 5-pin connector. Measure resistance between connector terminals No. 1 and 2. Resistance should be 4200-7800 ohms. Connect positive battery voltage to connector terminal No. 4. Connect negative battery voltage to connector terminal No. 5. Connect ohmmeter between connector terminals No. 2 and 3. Lever should move smoothly to face (vent) position and 3600-6700 ohms should be present. Reverse leads. Lever should move smoothly to defrost (DEF) position and 600-1100 ohms should be present. (Scheme 22)

Scheme 22

AMBIENT TEMPERATURE SENSOR

1. Disconnect ambient temperature sensor, located behind radiator, above cooling fan. Measure sensor resistance while heating sensor. See «AMBIENT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS»(ref-98934-S08259966682001072500000) table.
2. If resistance is not as specified, replace sensor. If resistance is within specification, check wiring harness and connectors between sensor and A/C control assembly. Repair harness and connectors as necessary. If wiring harness and connectors are okay, substitute a known-good A/C control assembly. Retest system. AMBIENT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS Sensor Temperature - °F (°C) (1) Ohms 77 (25) 1600-1800 144 (40) 500-700 (1) As temperature increases, resistance should gradually decrease.

EVAPORATOR TEMPERATURE SENSOR

Remove front or rear evaporator temperature sensor, located at evaporator. Measure sensor resistance at temperatures specified. See EVAPORATOR TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS table. If resistance is not as specified, replace sensor.

EVAPORATOR TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS

POSITIVE TEMPERATURE COEFFICIENT (PTC) HEATER

Remove PTC heater. See PTC HEATER under REMOVAL & INSTALLATION. Measure continuity between PTC heater connector terminals No. 1 and 2, and between terminals No. 3 and 4. (Scheme 23) If continuity is present, check wiring between PTC heater, heater relays and ground. See WIRING DIAGRAMS. Repair wiring as necessary. If continuity is not present, replace PTC heater.

Scheme 23

RELAYS

Note. For relay identification (Scheme 24)and (Scheme 25).

Clutch, Cooling Fan No. 1 & 3, Heater No. 1 & 2 & Water Pump Relays

For testing, see CLUTCH, COOLING FAN NO. 1 & 3, HEATER NO. 1 & 2, & WATER PUMP RELAYS SPECIFICATIONS table.

CLUTCH, COOLING FAN NO. 1 & 3, HEATER NO. 1 & 2, & WATER PUMP RELAYS SPECIFICATIONS

Cooling Fan No. 2 Relay

For testing, see COOLING FAN NO. 2 RELAY SPECIFICATIONS table.

COOLING FAN NO. 2 RELAY SPECIFICATIONS

Heater Main Relay

For testing, see HEATER MAIN RELAY SPECIFICATIONS table.

HEATER MAIN RELAY SPECIFICATIONS

Heater No. 3 Relay

For testing, see HEATER NO. 3 RELAY SPECIFICATIONS table.

HEATER NO. 3 RELAY SPECIFICATIONS

Scheme 24

Scheme 25

ROOM TEMPERATURE SENSOR

Disconnect front or rear room temperature sensor 2-pin connector. Measure resistance between sensor terminals No. 1 and 2 at specified temperature. See ROOM TEMPERATURE SENSOR RESISTANCE table. If resistances are not to specification, replace front room temperature sensor.

ROOM TEMPERATURE SENSOR RESISTANCE

SOLAR SENSOR

Remove solar sensor from top center of instrument panel. Disconnect harness connector. Cover sensor with cloth. Measure resistance between sensor terminals. Remove cloth. Subject sensor to bright light. Measure resistance between sensor terminals. See SOLAR SENSOR RESISTANCE SPECIFICATIONS table. If resistance is not as specified, replace sensor.

SOLAR SENSOR RESISTANCE SPECIFICATIONS

WATER VALVE SERVOMOTOR

1. Remove water valve servomotor. Measure resistance between water valve servomotor connector terminals No. 1 (Blue/Red wire) and No. 2 (Blue/Yellow wire). If resistance is 4200-7800 ohms, go to next step. If resistance is not 4200-7800 ohms, replace water valve servomotor.
2. Connect ohmmeter between terminals No. 2 and 3. Apply positive battery voltage to servomotor terminal No. 5 and ground terminal No. 4. Operate water valve servomotor. Reverse battery and ground leads. Resistance should be as specified for each position. See «WATER VALVE SERVOMOTOR RESISTANCE SPECIFICATIONS»(ref-98934-S24213858032001081100000) table.
3. If resistances are not to specification, replace water valve servomotor. If resistances are to specification, inspect wiring harness and connectors between servomotor and A/C control assembly. Repair as necessary. If wiring harness and connectors are okay, substitute a known-good A/C control assembly and retest system.

WATER VALVE SERVOMOTOR RESISTANCE SPECIFICATIONS

CONDENSER

Note. Condenser is integral with radiator.

WATER PUMP