DTC P144C: Open in Secondary Air Injection System Heater Control Circuit; DTC P144D: Short in Secondary Air Injection System Heater Control Circuit [08/2013 - ]: Procedure

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the air pump heater relay (AIR PMP HTR) from the engine room relay block.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	Battery voltage not applied	10 kΩ or higher
   	Battery voltage applied to terminals 1 and 2	Below 1 Ω

NG → REPLACE AIR PUMP HEATER RELAY (AIR PMP HTR) 

OK: Go to next step 

1. Remove the air pump heater relay (AIR PMP HTR) from the engine room relay block.
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   2 (Air pump heater relay (AIR PMP HTR)) - Body ground	Ignition switch ON	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *1	Engine Room Relay Block
   *2	Air Pump Heater Relay (AIR PMP HTR)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the air pump heater relay (AIR PMP HTR) from the engine room relay block.
2. Disconnect the B49 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1 (Air pump heater relay (AIR PMP HTR)) - B49-20 (HAI1)	Always	Below 1 Ω
   1 (Air pump heater relay (AIR PMP HTR)) or B49-20 (HAI1) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4