DTC Check / Clear

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DIAGNOSTIC CODE

Starting diagnostic mode (all elements come on during the switch check mode)
1. Turn off the audio system and turn the ignition switch to ACC. While pressing the preset switches "1" and "6" at the same time, press the "DISC" switch 3 times.
  HINT:
  - When the system enters the diagnostic mode, a beep sound is emitted 3 times and all the elements turn on during the switch check mode.
  - It takes about 40 seconds to complete the check.
  - Turn all the elements in the LCD on.
  - When pressing switch, confirm that a beep sound is emitted.
    
    Fig 1: Identifying Disc Switch
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Service check screen

Press the "SEEK TRACK UP" switch to enter the "Service Check Screen".

In the service check mode, the system check and the diagnostic memory check are performed, and the check results are displayed in numerical order of the component codes (physical address).

TERMS MEANING CHART

Terms	Meaning
Component code (physical address)	Three-digit code (in hexadecimal) given to each component of AVC-LAN. Corresponding to its function, individual symbol is provided.
Logical address	Two-digit code (in hexadecimal) given to each function and component unit in each component of AVC-LAN.

Code No. (physical address) List

CODE NO. LIST REFERENCE CHART

Code No. (physical address)	Equipment Name
190	Radio receiver (Audio head unit)
1C6	Network gateway ECU
440	Stereo component amplifier

Finishing diagnostic mode
1. Press the "DISC" switch for 2 seconds or more, or turn the ignition switch OFF.

CHECK DIAGNOSTIC MODE

HINT:

Illustrations may differ from the actual vehicle depending on the device settings and options.

Start the diagnostic mode.

Read the system check result.

Press the "SEEK TRACK" switch to see the check result of each component.
The component device code (physical address) is displayed first, and then the check result follows.
HINT:

If all check results are "good", the system determines that no DTC exists.

Fig 2: Display Check Result
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check result display

RESULT REFERENCE CHART

Display	Original Language	Meaning	Action to be taken
good	Good (normal)	No DTCs are detected in both "System Check Mode" and "Diagnostic Memory Mode".	-
nCon	No connection	System recognized component when it was registered, but component gives no response to "Diagnostic Mode ON Request"	Check power source circuit and communication circuit of component indicated by component code (physical address).
ECHn	Exchange	One or more DTCs for "Exchange" are detected in either "System Check Mode" or "Diagnostic Memory Mode".	Go to detailed information mode to check trouble area on DTC list.
CHEC	Check	When no DTCs are detected for "Exchange", one or more DTCs for "Check" are detected in either "System Check Mode" or "Diagnostic Memory Mode", on DTC list.	Go to detailed information mode to check trouble area on DTC list.
Old	Old version	Old DTC application is identified and DTC is detected in either "System Check Mode" or "Diagnostic Memory Mode".	-
nrES	No response	Device gives no response to "System Check Mode ON Request", "System Check Result Request" or "Diagnostic Memory Request".	Check power source circuit and communication circuit of component indicated by component code (physical address).

To perform the service check again, press the preset switch "1".

Detailed information mode (when displaying the DTC for a trouble component)

With "CHEC" or "ECHn" being displayed, press the preset switch "2" to go to the detailed information mode.
Press the "SEEK TRACK" switch to display the "System Check Result (SYS)" and "Diagnostic Memory Response (CODE)".

Fig 3: Display DTC Information In Service Check Mode

Displayed items in detailed information mode

DISPLAYED ITEMS INFORMATION MODE CHART

Division Code for DTC Display	Meaning	The order of detailed information displayed when the "SEEK TRACK UP" switch is pressed (the order is reversed when the "SEEK TRACK DOWN" switch is pressed)
SyS	System check result is displayed.	Logical address → DTC
COdE	Diagnostic memory check result is displayed.	Logical address → DTC → Sub code → Connection confirmation number → The number of times of occurrence

Check the trouble area on the DTC list.
To return to the service check mode, press the preset switch "3".

CLEAR DTC
1. Clearing individual DTC memory (when clearing the memory of DTCs detected in the past individually)
  1. Press the preset switch "5" for 2 seconds or more while "ECHn" is displayed in the service check mode or during the detailed information mode.
    HINT:
    - A beep sound is emitted once when the DTC memory is completely cleared.
    - When the DTC memory is cleared, only the component code (physical address) is displayed for the target component.
    - To check DTCs, press the preset switch "1" and perform the service check again.
2. Clearing entire DTC memory (when clearing entire memory of DTCs detected in the past)
  1. Start the diagnosis mode after repairing the trouble area.
  2. Press the preset switch "5" for 2 seconds or more ("CLR" is displayed at this time).
    HINT:
    - A beep sound is emitted once when the DTC memory is completely cleared.
    - When the DTC memory for all components is cleared, only the component codes (physical address) are displayed.
  3. Press the preset switch "1" to perform the service check again, and check that no DTCs are displayed for all the component codes (physical address).
3. Finishing diagnostic mode
  1. Press the "DISC" switch for 2 seconds or more, or turn the ignition switch OFF.