DTC Check/Clear

DTC CHECK/CLEAR (Using Mayday Switch)
HINT:

Turn the engine switch on (IG), wait 5 seconds, and then check the DTC.
1. Current DTC check
  With the engine switch on (IG), press and hold the PTT button, and then press the VOL+ button 5 times within 15 seconds.
2. Historic DTC check
  With the engine switch on (IG), press and hold the PTT button, and then press the VOL- button 5 times within 15 seconds.
3. Clear historic DTC
  With the engine switch on (IG), press and hold the PTT button, and then press the door unlock switch of the power window regulator master switch 5 times within 15 seconds.
DTC CHECK/CLEAR (Using Techstream)
1. Check DTC
  1. Connect the Techstream to the DLC3.
  2. Turn the engine switch on (IG).
  3. Turn the Techstream on.
  4. Enter the following menus: Body Electrical/Mayday Gateway/Trouble Codes.
  5. Read the DTCs.
2. Clear DTC
  1. Connect the Techstream to the DLC3.
  2. Turn the engine switch on (IG).
  3. Turn the Techstream on.
  4. Enter the following menus: Body Electrical/Mayday Gateway/Trouble Codes.
  5. Erase the DTCs.
LED BLINKING PATTERN
When the system is in the diagnosis mode, the red and green LEDs on the mayday switch will blink in the applicable pattern. The blinking pattern shown in the illustration is an example of DTC 3-2 and 4-3.

DTCs will be output in numerical order.

A set of DTC blinking patterns will be output twice.

Fig 1: LED Blinking Pattern
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
EXIT DIAGNOSIS MODE
Diagnosis mode can be exited by turning the engine switch off.

INFRASTRUCTURE TROUBLESHOOTING

LEXUS Link system

LEXUS LINK SYSTEM SYMPTOM CHART

Item	Symptom	Cause	Check Method	Countermeasure
Activation	Cannot be activated	Infrastructure Mayday ECU	Check if phone connects to LEXUS Link call center when SERVICES button is pressed If it does, problem may be in LEXUS Link call center/infrastructure If mayday ECU is within cover service area of system, replace it*1	If problem is in LEXUS Link call center/infrastructure, Inform TMS and request repairs If problem is in mayday ECU, replace it*1 In some cases, moving vehicle to another location and trying to activate service connection again can solve problem
Service Call Emergency Call	Cannot connect to LEXUS Link call center Connection retry frequently occurs	Infrastructure Telephone antenna (Cellular phone antenna)*2 Mayday ECU	Run vehicle, check whether connection is related to place or area3 If it is not related to place or area, problem may be in may day ECU or telephone antenna (cellular phone antenna)2 If it is related to place or area, problem may be in Infrastructure	If problem is not infrastructure, check wiring connection of telephone antenna (cellular phone antenna)*2 If there are no connection problems, check mayday ECU
	Cannot connect to LEXUS Link call center Connection retry frequently occurs	Infrastructure	Setup of infrastructure may be wrong	Cellular carrier in area is not set up to accept Mobile Identification Number (MIN) for mayday ECU on vehicle Inform TMS and request setup
	Disconnection immediately after connection	Infrastructure Telephone antenna (Cellular phone antenna)*2 Mayday ECU	Run vehicle, check whether connection is related to place or area3 If It is not related to place or area, problem may be in mayday ECU or telephone antenna (cellular phone antenna)2 If it is related to place or area, problem may be in infrastructure	If problem is not Infrastructure, check wiring connection of telephone antenna (cellular phone antenna)*2 If there are no problems with above areas, check mayday ECU
	After connecting to LEXUS Link call center and driving long distance, connection worsens	Infrastructure	There is difference between registered information of location during activation and information in current location, leading to bad LEXUS Link call center connection	Contact LEXUS Link call center with service call, ask to change registration Information and download setup Information again
	LEXUS Link system has no response after messages "Connecting to LEXUS Link" or "Connecting to LEXUS Link Emergency"	Infrastructure Telephone antenna (Cellular phone Antenna)*2 Mayday ECU	Run vehicle, check whether connection is related to place or area3 If it is not related to place or area, problem may be in mayday ECU or telephone antenna (cellular phone antenna)2 If It is related to place or area, problem may be in infrastructure	Cellular electronic wave condition in area may cause this problem As vehicle data reaches LEXUS Link call center, call center will call back to vehicle
	Communication quality is abnormal	Infrastructure LEXUS Link system	Run vehicle, check whether connection is related to place or area3 If it is not related to place or area, problem may be in mayday ECU or telephone antenna (cellular phone antenna)2 If it is related to place or area, problem may be in Infrastructure	If problem is not in Infrastructure, check vehicle equipment such as mayday switch, etc.
HINT: 1: If replacement of the ECU is necessary, replace the mayday battery (backup battery) together with the ECU. After the replacement, register the ECU. 2: Telephone antenna includes peripheral parts such as the telephone antenna rod, telephone antenna base, antenna wire, etc. *3: When running the vehicle, make sure it is in the LEXUS Link service area. If on a level surface, the vehicle may only need to be driven a short distance before a connection can be made. If in a mountainous area, the vehicle may have to be driven a long distance before the connection can be made.