Diagnostic Trouble Code 1-2-3
Diagnostic trouble code (DTC) 1-2-3Circuit: RESUME button to 6T
Diagnostic trouble code (DTC) 1-2-3 is given when the RESUME button is activated so terminal 6T in the control module receives voltage.
If code 1-2-3 is not given, the voltage is probably constantly high (battery voltage 12V) or low (OV).
First check that there is voltage leading to the selector. If either of the trouble codes 1-3-1,1-1-3 or 2-1-3 are given, it shows there is voltage to the selector. If neither of the above codes is obtainable, the voltage leading to the selector must be checked. See E1 - E4.
If there is voltage to and from the selector, check voltage at connector 6T in the control module plinth. See E6.
Checking voltage to the selector
Voltage feed E1
Check first that fuse 28 for 15-feed is sound.
Remove steering wheel covers, which are held in place by Torx-screws, T15 above and T25 below.
Checking voltage to the selector E2
Ignition ON.
Voltmeter connected between ground and terminal 2 in the selector connector should show battery voltage.
In the event of a fault: Check wire leading to the selector, and that fuse 28 still is sound.
Checking voltage to the selector, with the switch set to ON. E3
There is voltage; connect voltmeter between ground and terminal 1 on the selector connector. There should be battery voltage in the ON position.
If not, replace selector.
Voltmeter shows battery voltage on 1: check that there is voltage on terminal 3 in the selector connector, see below.
Checking voltage from terminal 3 in the selector connector. E4
Ignition ON.
Voltmeter connected between ground and terminal 3 in the selector connector should show battery voltage when the RESUME button is depressed.
In the event of a fault: try with another selector.
Checking voltage to 6T in the control module base
Remove control module E5
Remove cover from fuses and relays in the engine house. Remove the control module of the cruise control.
Voltage feed E6
Ignition ON.
Selector switch set to ON. Voltmeter connected between ground and terminal 6T in the control module base should display battery voltage when the RESUME button is pressed in.
In the event of a fault: check wire from selector terminal 3 to terminal 6T in the control module base.
If the wire is OK: try with another selector.