DTC C1791: Absorber Control Switch Circuit (Test Mode DTC) [08/2019 - ]: Procedure

1. Turn the engine switch off.
2. Connect the Techstream to the DLC3.
3. Turn the engine switch on (IG), and turn the Techstream main switch on.
4. Enter the following menus: Chassis / Air suspension / Data List.
   AIR SUSPENSION
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Damping Control Switch	Absorber control switch / NORMAL, COMFORT or SPORT	Indicates current absorber control switch position	-

5. Check that the value displayed on the Techstream changes by operating the absorber control switch "COMFORT" or "SPORT".

   OK

   Absorber control switch value changes.

   RESULT
   
   

   Result	Proceed to
   NG	A
   OK (When troubleshooting according to the Problem Symptoms Table)	B
   OK (When troubleshooting according to the DTC Chart)	C

Result: 

B 

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

(Refer to PROBLEM SYMPTOMS TABLE [08/2015 - ] )

Result: 

C 

USE SIMULATION METHOD TO CHECK 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ] )

Result: 

A 

See step  2

1. Turn the engine switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Remove the absorber control switch.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   7 (GND) - 8 (ECU1)	COMFORT position	Below 1 Ω
   	Normal position	10 kΩ or higher
   7 (GND) - 9 (ECU2)	SPORT position	Below 1 Ω
   	Normal position	10 kΩ or higher

Result: 

NG 

REPLACE SUSPENSION CONTROL SWITCH 

(Refer to REMOVAL [08/2015 - ] )

Result: 

OK 

See step  3

1. Disconnect the O59 ECU connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H71-8 (ECU1) - O59-23 (TSW1)	Always	Below 1 Ω
   H71-9 (ECU2) - O59-22 (TSW2)	Always	Below 1 Ω
   H71-7 (GND) - Body ground	Always	Below 1 Ω
   H71-8 (ECU1) or O59-23 (TSW1) - Body ground	Always	10 kΩ or higher
   H71-9 (ECU2) or O59-22 (TSW2) - Body ground	Always	10 kΩ or higher

Result: 

OK 

REPLACE SUSPENSION CONTROL ECU 

(Refer to REMOVAL [08/2015 - ] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR