Inspection Procedure

1. Check that the tachometer operates properly while the engine is idling.

   OK: 

   Tachometer operate properly while engine is idling. 

NG: Go to step 2 

OK: REPLACE COMBINATION METER ASSEMBLY (METER ECU) 

1. Disconnect the K31 meter connector.
2. Measure the resistance and voltage of the wire harness side connector.

   Standard Resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   K31-40 (E2) - Body ground	Below 1 Ω

   Standard Voltage 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   K31-21 (B) - Body ground	10 to 14 V

Fig 1: Identifying Combination Meter Assembly Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

Fig 2: Identifying Combination Meter Assembly And Network Gateway ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the K31 and K66 ECU connectors.
2. Disconnect the K44 sensor connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   TESTER SPECIFIED CONDITION
   
   

   Tester Condition	Specified Condition
   K31-25 (MPX+) - K66-13 (MPI2)	Below 1 Ω
   K31-5 (MPX-) - K44-13 (MPX1)	Below 1 Ω

   Result 

   RESULT CHART
   
   

   Result	Proceed to
   Both are OK	A
   One is OK	B
   Both are OK	C

B: REPLACE COMBINATION METER ASSEMBLY AND WIRE HARNESS CONNECTOR 

C: REPAIR OR REPLACE HARNESS AND CONNECTOR 

A: REPLACE COMBINATION METER ASSEMBLY (METER ECU)