Inspection Procedure

HINT:

• If DTC C1774/74 (power source circuit) is displayed, perform the inspection necessary for DTC C1774/74 first ( DTC C1774/74 POWER SOURCE CIRCUIT ).
• If DTC C1713/13 (right rear height control sensor circuit), C1714/14 (left rear height control sensor circuit) and C1761/61 (ECU malfunction) are output at the same time, perform the inspection necessary for DTC C1761/61 first.

1. INSPECT HEIGHT CONTROL OFF INDICATOR LAMP 
   1. Turn the ignition switch ON, and check the height control OFF indicator lamp.

   Result: 

   1. A: Height control OFF indicator lamp comes on 
   2. B: Height control OFF indicator lamp does not come on 
   1. B: REPLACE SUSPENSION CONTROL ECU 
   2. A: GO TO NEXT STEP. 
2. INSPECT SUSPENSION CONTROL ECU (HEIGHT CONTROL SENSOR SUB-ASSY REAR POWER SOURCE) 
   1. Remove the suspension control ECU with connectors being connected.
   2. Turn the ignition switch ON, and measure voltage between terminal S18-20 (SBR2) and S20-1 (GND) and between terminal S18-22 (SBL2) and S20-1 (GND) of the suspension control ECU connector.
      Fig 1: Measuring Voltage Between Terminal S18-20 (SBR2) And S20-1 (GND)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard: 4.5 to 5.5 V 

   1. NG: CHECK HEIGHT CONTROL SENSOR SUB-ASSY CIRCUIT (  DTC C1713/13 RIGHT REAR HEIGHT CONTROL SENSOR CIRCUIT, DTC C1714/14 LEFT REAR HEIGHT CONTROL SENSOR CIRCUIT  ) 
   2. OK: GO TO NEXT STEP. 
3. INSPECT SUSPENSION CONTROL ECU (ACCELERATION SENSOR POWER SOURCE) 
   1. Turn the ignition switch ON, and measure voltage between terminal S19-18 (SBR) and S20-1 (GND) and between terminal S19-21 (SBR3) and S20-1 (GND) of the suspension control ECU connector.
      Fig 2: Measuring Voltage Between Terminal S19-18 (SBR) And S20-1 (GND)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard: 4.5 to 5.5 V 

   1. NG: CHECK ACCELERATION SENSOR CIRCUIT (  DTC C1715/15 RIGHT FRONT ACCELERATION SENSOR CIRCUIT, DTC C1716/16 LEFT FRONT ACCELERATION SENSOR CIRCUIT, DTC C1717/17 REAR ACCELERATION SENSOR CIRCUIT, DTC C1791/91 RIGHT FRONT ACCELERATION SENSOR CIRCUIT, DTC C1792/92 LEFT FRONT ACCELERATION SENSOR CIRCUIT, DTC C1793/93 REAR ACCELERATION SENSOR CIRCUIT  ) 
   2. OK: GO TO NEXT STEP. 
4. INSPECT SUSPENSION CONTROL ECU (ECU POWER SOURCE) 
   1. Turn the ignition switch OFF, and measure voltage between terminal S19-6 (B) and S20-1 (GND) and between terminal S19-6 (B) and S20-5 (GND2) of the suspension control ECU connector.
      Fig 3: Measuring Voltage Between Terminal S19-6 (B) And S20-1 (GND)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard: 10 to 14 V 

   1. NG: CHECK POWER SOURCE CIRCUIT (  DTC C1774/74 POWER SOURCE CIRCUIT  ) 
   2. OK: GO TO NEXT STEP. 

      REPLACE SUSPENSION CONTROL ECU