Volvo: Volvo 850 Year 1994, transmission control module, alldata online

Question
How to computer reset (lambda light is on)?
We have replaced the oxygen censor already.
Thanks.

Answer
Lydia,
You need to use the blinker box under the hood right front. Plug the pig tail into A2 push the button for a second read and record the flashing light (fault codes) push it a seconf time makeing sure all the codes are read,when you get back to the first code, push and hold the button for 5 seconds release when the light lights back up hold the button again for the 5 seconds. Then push the button and make sure the code you get back is 111.

ALLDATA Online - 1994 Volvo 850 L5-2.4L VIN 55 B5254S

1994 Volvo 850 L5-2.4L VIN 55 B5254S
Vehicle Level Powertrain Management Computers and Control Systems Testing and Inspection Reading and Clearing
Diagnostic Trouble Codes Clearing Diagnostic Trouble Codes Transmission Trouble Codes Diagnostic Test
Modes Diagnostic Test Mode 1
Diagnostic Test Mode 1
Notes
DTM 1:
Stored Diagnostic Trouble Codes (DTCs) can be read off and erased in DTM 1. A short press on
the button on the DLC will start the DTC read-off procedure. If the control module replies by flashing
code 1-1-1 no faults have been registered, so no DTCs have been stored. If the control module
replies using any other flashing code sequence it is a DTC that has been stored. Use the table in
the section D. Diagnostic Codes to identify the reason for the DTC being set.
The control module can store a maximum of five DTCs. The fault must be corrected and the DTC
erased before further DTCs can be stored in the transmission control module.
Erasing DTCS
ALLDATA Online - 1994 Volvo 850 L5-2.4L VIN 55 B5254S - Diagnostic Test Mode 1 Page 2
It is only possible to clear the data link connector (DLC) of codes after reading off all the codes at
least once and the first code stored at least twice. The procedure for erasing stored DTCs is as
follows:
Ignition ON
Press the button and hold down for more than five seconds. Release the button.
Wait for the LED to light.
Press the button again and hold down for more than five seconds. Release the button.
Make sure that the DTC's have been cleared by reading off the DTCs again.