On-Vehicle Inspection

DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
CAUTION: Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to prevent airbag and seat belt pretensioner activation.
REMOVE PTC HEATER RELAY (PTC HTR1, PTC HTR 2, PTC HTR 3)
1. Remove the 3 PTC heater relays from the No. 5 relay box.
  
  Fig 1: Identifying PTC Heater Relays From No. 5 Relay Box
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT PTC HEATER RELAY (PTC HTR 2)

Measure the resistance of the relay.

Fig 2: Inspecting PTC Heater Relay

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard resistance

PTC HEATER RELAY (PTC HTR 2)

Tester Connection	Condition	Specified Condition
3-5	When battery voltage is not applied between terminals	10 kΩ or higher
3-5	When battery voltage is applied to terminal 1 and 2	Below 1 Ω

If the result is not as specified, replace the relay.

INSPECT PTC HEATER RELAY (PTC HTR 1, PTC HTR 3)

Measure the resistance of the magnet clutch relay.

Fig 3: Inspecting PTC Heater Relay (PTC HTR 1, PTC HTR 3)

Standard resistance

PTC HEATER RELAY (PTC HTR 1, PTC HTR 3)

Tester Connection	Condition	Specified Condition
3-5	When battery voltage is not applied between terminals	10 kΩ or higher
3-5	When battery voltage is applied to terminal 1 and 2	Below 1 Ω

If the result is not as specified, replace the relay.

INSTALL PTC HEATER RELAY
CONNECT CABLE TO NEGATIVE BATTERY TERMINAL
PERFORM INITIALIZATION
1. Perform initialization (see INITIALIZATION ).
  NOTE: Certain systems need to be initialized after disconnecting and reconnecting the cable from the negative (-) battery terminal.