Solar Ventilation System (Diagnostics & Circuit Tests) (Base): Overview Toyota Prius Plug-in

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1. GENERAL PRECAUTION While using the battery during inspection, do not bring the positive (+) and negative (-) tester probes too close to each other as a short circuit may occur.
2. PRECAUTIONS WHEN USING TECHSTREAM When using the Techstream with the power switch off to troubleshoot: Connect the Techstream to the vehicle, and turn a courtesy light switch on and off at 1.5-second intervals until communication between the Techstream and vehicle begins. After all DTCs are cleared, check if the malfunction occurs again 6 seconds after the power switch is turned on (IG).
3. OPERATION PRECAUTIONS The solar ventilation system operates using electrical power generated by the moon roof glass assembly (solar panel). Therefore, the solar ventilation system stops operating when the amount of electricity generated by the moon roof glass assembly (solar panel) becomes insufficient. HINT: If the solar ventilation system stops operating due to the moon roof glass assembly (solar panel) generating an insufficient amount of electricity, the solar ventilation system will resume operating after output from the moon roof glass assembly (solar panel) has recovered. The solar ventilation system may degrade the air quality in the cabin or lower air conditioning efficiency depending on the usage environment. When ventilation is not necessary, turn the solar ventilation switch off. NOTE: Depending on the usage environment, exhaust emissions from other vehicles or polluted outside air may enter in the cabin. Depending on the strength of the sunlight when the outside temperature is low, the cabin temperature may become low because of the cool air drawn into the cabin due to solar ventilation system operation. When the cabin temperature is initially low, the temperature may rise because the cool air escapes from the cabin due to solar ventilation system operation. If it is not necessary to operate the solar ventilation system while working on it, turn the solar ventilation switch off. WARNING: Depending on the usage environment, performing repairs with the solar ventilation switch on may cause the blower motor to operate unexpectedly, resulting in various hazards. This can lead to damage to parts or a serious injury. Before disconnecting the moon roof glass assembly (solar panel) connector, make sure to cover the entire moon roof glass assembly (solar panel) with a material such as thick fabric which blocks sunlight. WARNING: The moon roof glass assembly (solar panel) generates electricity from sunlight and other light sources. If the moon roof glass assembly (solar panel) connector is touched while the moon roof glass assembly (solar panel) is generating electricity, an accidental short circuit or electric shock may occur, causing serious injury. HINT: The moon roof glass assembly (solar panel) always generates electricity when exposed to light. When exposed to a light source such as sunlight, approximately 3.6 A and 22 V will be generated.

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1. GENERAL The solar ventilation system ventilates the cabin when the vehicle is parked in an extremely hot environment. Ventilation is provided by the system operating the blower motor using electricity generated by the moon roof glass assembly (solar panel) installed on the roof. HINT: The solar ventilation system may operates even when not all conditions of the following table are met. Meeting all conditions of the following System Operation Condition Reference Table is necessary to obtain precise inspection results. SYSTEM OPERATION CONDITIONS REFERENCE TABLE Item Condition Amount of sunlight A sufficient amount of sunlight is received by the moon roof glass assembly (solar panel). (The amount of sunlight on a cloudless day between 11:00 and 14:00 is typically sufficient for operation.) Moon roof glass assembly (solar panel) status The moon roof glass assembly (solar panel) is not in the shade No fallen leaves or dirt is present on the moon roof glass assembly (solar panel) Ambient temperature 20 to 40°C (68 to 104°F) Shortly after the solar ventilation system has been activated, it may stop the blower motor if the sunlight is not sufficient even when the rest of the system operation conditions reference table are met. Activation Control When the solar ventilation switch is turned on while the power switch is on (IG): The inlets will be changed to fresh air mode and the outlets will be changed to face mode approximately 1 minute after the power switch is turned off. In addition, the blower motor will be activated and start ventilating the cabin approximately 10 minutes after the power switch is turned off. HINT: In order to enhance ventilation efficiency, the inlets will be changed to fresh air mode and the outlets will be changed to face mode automatically when the solar ventilation switch is turned on while the power switch is on (IG). When the solar ventilation switch is turned on after the power switch is turned off: The blower motor will be activated and start ventilating the cabin approximately 10 minutes after the solar ventilation switch is turned on. HINT: Inlet and outlet modes will remain unchanged when the solar ventilation switch is turned on after the power switch is turned off. Stop Control When the solar ventilation switch is turned off or the power switch is turned on (IG), the solar ventilation system will stop operating. HINT: After the power switch is turned on (IG), both the inlets and outlets return to the mode that they were in before the power switch was turned off.
2. FUNCTION OF MAIN COMPONENTS The solar ventilation system consists of the following components: Component Function Moon roof glass assembly (solar panel) Generates power from sunlight and supplies system power to the solar ventilation ECU. Solar ventilation ECU Activated by power generated by the moon roof glass assembly (solar panel). Activates the solar ventilation system by receiving an on signal from the solar ventilation switch and an off signal from the vehicle power switch. Sends a solar ventilation system condition signal to the A/C amplifier. Operates the blower motor when the solar ventilation system is turned on. Solar ventilation switch Turns the solar ventilation system on or off. Solar ventilation relay Switches the power supply source for the blower motor between the auxiliary battery and solar ventilation ECU according to the power switch condition. Blower motor Performs ventilation when the power switch is off based on instructions from the solar ventilation ECU. Changes its speed according to the amount of sunlight received by the moon roof glass assembly (solar panel). A/C amplifier Activates the air outlet control servo motor and air inlet control servo motor according to the signals from the solar ventilation ECU. Receives solar ventilation system condition signal from the solar ventilation ECU and sends a solar ventilation system condition signal via CAN. Air inlet control servo motor Switches the inlets to fresh air mode based on signals from the A/C amplifier. Air outlet control servo motor Switches the outlets to face mode based on signals from the A/C amplifier.

DESCRIPTION

The solar ventilation system activates when the vehicle power switch is off. If the solar ventilation switch has been turned on, the solar ventilation ECU checks that the vehicle power switch is off and then activates the solar ventilation system.

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The solar ventilation system and air conditioning system use the same blower motor for ventilation.

In order to be driven by each system, the blower motor switches between two different power sources using the solar ventilation relay. When the power switch is off, power from the solar ventilation system is supplied to the blower motor and when the power switch is in a mode other than off, power from the air conditioning system is supplied to the blower motor.

The blower motor controls its operation and speed using the power and signals supplied by the solar ventilation ECU when the power switch is off.

Changes its speed according to the amount of sunlight received by the moon roof glass assembly (solar panel).

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The solar ventilation system can operate when the solar ventilation switch is on and the moon roof glass assembly (solar panel) generates the necessary amount of electricity.

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For the solar ventilation system, the moon roof glass assembly (solar panel) generates electricity using sunlight to generate the required power.

The electricity generated by the moon roof glass assembly (solar panel) is sent to the solar ventilation ECU and used as the power source for the solar ventilation system.

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1. INSPECT MOON ROOF GLASS ASSEMBLY (SOLAR PANEL) Leave the vehicle for 10 minutes in a location where the following conditions are met, and then measure the voltage. SYSTEM OPERATION CONDITIONS REFERENCE TABLE Items Condition Amount of sunlight A sufficient amount of sunlight is received by the moon roof glass assembly (solar panel). (The amount of sunlight on a cloudless day between 11:00 and 14:00 is typically sufficient for operation.) Moon roof glass assembly (solar panel) status The moon roof glass assembly (solar panel) is not in the shade No fallen leaves or dirt is present on the moon roof glass assembly (solar panel) Ambient temperature 20 to 40°C (68 to 104°F) NOTE: To ensure stable generation of voltage by the moon roof glass assembly (solar panel), make sure to park the vehicle in a location where the system operation conditions reference table are satisfied. Disconnect the solar ventilation ECU connector. WARNING: The moon roof glass assembly (solar panel) generates electricity when exposed to a light source such as sunlight. If an inspection of the moon roof glass assembly (solar panel) is performed while electricity is being generated, work carefully in order to prevent an accidental short circuit or electric shock. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition L22-11 (SBI) - L22-1 (GND) System operation conditions reference table are met. 12 V or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Solar Ventilation ECU) NG --> See step 3 OK: Go to next step
2. READ VALUE USING TECHSTREAM Reconnect the solar ventilation ECU connector. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Air Conditioner / Data List. Check the value(s) by referring to the table below. Check that the Solar Voltage value in the Data List is 10 V or higher. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Solar Voltage Solar panel voltage / Variable, 10V les, 10V-11V, 11V-12V, 12V-13V, 13V-14V, 14V-15V, 15V-16V, 16V-17V, 17V-18V, 18V-19V, 19V-20V, 20V-21V, 21V-22V, 22V-23V or 23V ovr Actual generated voltage displayed System operation conditions reference table are met. Refer to «SYSTEM DESCRIPTION»(ref-551634-S17247647462013051500000). OK 10 V or higher HINT: If the Data List items are not displayed, inspect the communication circuit between the solar ventilation ECU and A/C amplifier. Refer to «Communication Circuit between Solar Ventilation ECU and A/C Amplifier»(ref-551634-S09158485452013051500000). NG --> See step 5 OK --> See step 4
3. CHECK HARNESS AND CONNECTOR (SOLAR VENTILATION ECU - SOLAR PANEL, BODY GROUND) Disconnect the solar ventilation ECU connector. Disconnect the moon roof glass assembly (solar panel) connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition L22-11 (SBI) - R15-1 (+B) Always Below 1 ohms L22-1 (GND) - Body ground Always Below 1 ohms L22-11 (SBI) - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Solar Ventilation ECU) *2 Front view of wire harness connector (to Moon Roof Glass Assembly (Solar Panel)) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 6
4. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-551634-S15930460602013051500000)
5. REPLACE SOLAR VENTILATION ECU. Refer to «REMOVAL»(/toyota/prius-plug-in/2012-2014/remont/automatic-hvac-system/#air-conditioning-system-service-information-base)
6. REPLACE MOON ROOF GLASS ASSEMBLY (SOLAR PANEL). Refer to «REMOVAL»(ref-551614-S14148913142013051500000)

The solar ventilation ECU communicates with the A/C amplifier using a direct line. The A/C amplifier checks the condition of the solar ventilation system based on signals sent via the direct line.

When this circuit malfunctions, Data List items for the solar ventilation system will not be displayed.

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1. CHECK HARNESS AND CONNECTOR (SOLAR VENTILATION ECU - A/C AMPLIFIER) Disconnect the solar ventilation ECU connector. Disconnect the A/C amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition L22-17 (SIND) - L17-26 (SSLR) Always Below 1 ohms L22-17 (SIND) - Body ground Always 10 kohms or higher TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Solar Ventilation ECU) *2 Front view of wire harness connector (to A/C Amplifier) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
2. REPLACE SOLAR VENTILATION ECU Replace the solar ventilation ECU with a known good one and check if the same problem occurs again. Refer to «REMOVAL»(/toyota/prius-plug-in/2012-2014/remont/automatic-hvac-system/#air-conditioning-system-service-information-base) . OK Same problem does not occur. NG --> See step 3 OK --> END (SOLAR VENTILATION ECU WAS DEFECTIVE)
3. REPLACE A/C AMPLIFIER. Refer to «REMOVAL»(/toyota/prius-plug-in/2012-2014/remont/automatic-hvac-system/#air-conditioning-system-service-information-base)

See also:
• REMOVAL