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Home >> Volvo >> 1991 >> 240 SE, AW70L >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Self-Diagnostics - Turbo System >> Control Function No. 1 >> Retrieving Codes
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Retrieving Codes

  1. Locate diagnostic unit, and remove its cover. Connect selector cable to socket No. 5. Turn ignition to ON position. Enter control function No. 1 (access codes) by pressing push button one time for at least one second and no more than 3 seconds.
    NOTE: Information on control function No. 3 appears later in article. There is no control function No. 2 for the turbo system. To enter control function No. 3, press push button 3 times for at least one second and no more than 3 seconds.
  2. Watch the Red LED and count the number of flashes in the 3-flash series. The flash series are separated by a 3 second interval. See Figure. Note all codes. Only 3 separate codes can be stored at once. If no codes are stored, the LED will flash a 1-1-1 to indicate turbo system is operating properly.
  3. If a fault code is received, refer to the TURBO SYSTEM FAULT CODES  table. Depress push button again and check for additional codes. Depress push button a third time if necessary. If first code repeats, no other codes are present.
  4. Diagnostic system memory is full when 7 codes are present. Those 7 codes must be repaired before further codes can be retrieved.
NOTE: Not all codes listed in TURBO SYSTEM FAULT CODES  table are used on every vehicle.
TURBO SYSTEM FAULT CODES (1)

Code Fault Repair
1-1-1 No Faults N/A
2-4-2  Turbo Control Valve (2) Check Turbo Control Valve
3-1-2  Knock Sensor Signal Check For Knocking
3-4-2  A/C Blocking Relay Check A/C Blocking Relay
4-2-1  Press. Sensor Signal (3) Check Turbo Control Valve
4-2-3  Throttle Pos. Sensor Check Sensor
4-3-1  Temp. Sensor Signal Check Sensor
4-2-4  Load Signal Check Load Signal
(1) See FAULT CODE TESTING under SELF-DIAGNOSTICS - TURBO SYSTEM .
(2) Resistance check.
(3) Mechanical check.