Height Control Sensor Circuit: Description

The height control sensor rear RH controls the resistance value based on changes vehicle height. The headlight beam level control ECU detects the changes in vehicle height from the transformed voltage. The headlight beam level control ECU outputs a constant voltage of 5 V to the SHB terminal of the height control sensor rear RH.

In the height control sensor sub-assembly rear RH, the voltage changes due to the resistance. The changes voltage is output from the SHRR terminal of the height control sensor rear RH to the headlight beam level control ECU, thus the vehicle's height is detected.

Fig 1: Height Control Sensor Sub-Assembly Rear RH Circuit Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. INSPECT HEIGHT CONTROL SENSOR SUB-ASSEMBLY REAR RH 
   1. Connect 3 dry cell batteries (1.5 V) in series.
   2. Remove the height control sensor sub-assembly rear.
   3. Connect the positive (+) lead from the battery to terminal 1 and the negative (-) lead from the battery to terminal 3.
   4. Measure the voltage between terminals 2 and 3 while slowly moving the link up and down.
      STANDARD VOLTAGE CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      L9-2 (SHRR) - L9-3 (SHG)	+45° (High)	Approx. 4.5 V
      L9-2 (SHRR) - L9-3 (SHG)	0° (Normal)	Approx. 2.5 V
      L9-2 (SHRR) - L9-3 (SHG)	-45° (Low)	Approx. 0.5 V

   NG: REPLACE HEIGHT CONTROL SENSOR SUBASSEMBLY REAR RH 

   Fig 1: Measuring The Voltage Between Terminals 2 And 3

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: Go to Next Step 

2. CHECK HARNESS AND CONNECTOR (HEIGHT CONTROL SENSOR REAR RH - HEADLIGHT BEAM LEVEL CONTROL) 
   1. Disconnect connector L9 of the height control sensor sub-assembly and connector A21 of the headlight leveling ECU assembly.
   Fig 2: Identifying Terminals Of Height Control Sensor Rear RH Connector
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Measure the resistance according to the value(s) in the table below.
      STANDARD RESISTANCE CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      A21-17 (SGR) - L9-1 (SHB)	Always	Below 1
      A21-19 (SHRL) - L9-2 (SHRR)	Always	Below 1
      A21-21 (SRB) - L9-2 (SHG)	Always	Below 1
      L9-3 (SHG) - Body ground	Always	10 k or higher
      L9-2 (SHRR) - Body ground	Always	10 k or higher
      L9-1 (SHB) - Body ground	Always	10 k or higher

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE