Q: How to remove and install the heater core on Scion xA?
A: A safe heater core removal starts with disconnecting the negative battery cable terminal while extending the waiting period to 90 seconds to avoid Air Bag and seat belt pretensioners from activating. Drain the engine coolant then discharge refrigerant from the system followed by removing the suction hose sub-assembly, liquid tube sub-assembly and heater water inlet hose and outlet hose through usage of pliers to remove the inlet hose clip. To begin disassembly reverse the process by first removing the instrument panel sub-assembly, lower instrument panel assembly, ECM, air conditioning blower assembly, air conditioning amplifier assembly, and defroster nozzle assembly after unclipping the part and detaching both claws. The defroster damper control cable sub-assembly and air mix damper control cable sub-assembly can be removed after disconnecting their inner and outer cables from each sub-assembly. The No. 1 instrument panel brace sub-assembly requires wire harness disconnect and bolt and nut removal before installation. You must disconnect the No. 2 and No. 1 air ducts rear before you can remove the heater radiator assembly by disconnecting the 3 connectors while removing the bolt and ground wire from the PTC heater and taking off the 2 nuts. To install the components begin with heater radiator assembly fittings using two nuts followed by wireless connection between ground wire and PTC heater as well as connector reattachment. You should first connect the rear ends of No. 1 and No. 2 air ducts then install air mix damper control cable sub-assembly and defroster damper control cable sub-assembly through inner and outer cable connections before installing the No. 1 instrument panel brace sub-assembly with 4 bolts and nut while connecting the wire harness. Begin by installing the defroster nozzle assembly through its two claws then place the clip before moving onto the air conditioning amplifier assembly and air conditioning blower assembly and ECM followed by lower instrument panel assembly and instrument panel sub-assembly. Reconnect the heater water outlet hose and inlet hose following the initial procedure before restoring the liquid tube sub-assembly and suction hose sub-assembly and subsequent connection of the cable to the negative battery terminal. After reconnecting the cable the system requires initialization regarding specific needs followed by SRS warning light inspection and adding engine coolant while charging the refrigerant before checking the engine and inspecting for leaks from both coolant and refrigerant.
Q: How to service and repair the heater core on Scion xB?
A: A technicians must begin heater core repair by discharging refrigerant from the refrigeration system through Special Service Tool: 09870-00015 07110-58060 (07117-58080, 07117-58090, 07117-78050, 07117-88060, 07117-88070, 07117-88080). Users should first disconnect the suction hose sub-assy and the liquid tube sub-assy A with Special Service Tool: 09870-00025 followed by removing the heater water inlet hose A by sliding its clip using pliers. After disconnection of the outer hose A follow the same approach. The technicians should remove the heater control knob followed by the instrument cluster finish panel sub-assy CTR and instrument panel sub-assy w/passenger Air Bag assy until they reach the instrument panel assy lower w/instrument panel reinforcement. First remove the defroster nozzle assembly with clip removal to free the claws then continue removing the ECM followed by the air conditioning blower assembly and defroster damper control cable sub-assembly when both outer and inner cables are disconnected and similar for the air mix damper control cable sub-assembly. Dismantle air duct rear No.2 along with air duct rear No.1 through the same procedure. To remove the heater radiator assembly begin by disconnecting the three connectors followed by unbolting and unearthing both the PTC heater and its attachments then use the two nuts to complete uninstallation. Start by removing the air duct assy after dislodging its 4 claws while subsequently removing the heater cover by unscrewing and separating the claws. To remove Cooler Wiring No.2 disconnect the 5 screws until the thermistor assembly becomes accessible for removal with a claw that can also release the clamp. Installation of the heater radiator unit sub-assembly requires you to first unscrew its bracket then remove the clamp followed by disconnecting the connector. Insert the defroster damper control cable sub-assy facing forward with the arm set at FACE position so that the control lever holds the inner cable end and the wire from the outer cable hooks onto the cable clamp securely without wire bending. The same installation sequence must be performed on the air mix damper control cable sub-assy while keeping the arm in MAX (COOL) position. COOL position. Reinstall the ECM together with instrument panel assy lower w/instrument panel reinforcement and the instrument panel sub-assy w/passenger Air Bag assy and both instrument cluster finish panel sub-assy CTR and heater control knob. The necessary next step includes the installation of liquid tube sub-assy A and suction hose sub-assy followed by engine coolant addition and refrigerant charging through Special Service Tool: 07110-58060 (07117-58060, 07117-58070, 07117-58080, 07117-58090, 07117-78050, 07117-88060, 07117-88070, 07117-88080) with a specified range of 380 plus or minus 30 g (13.9 plus or minus 1.1 oz.). First heat the engine while checking for coolant leaks alongside inspecting the refrigerant system for leaks.