FixVault

Check Key Warning Switch

DIAGNOSIS PROCEDURE CHART

Step Check Yes No
1 CHECK KEY WARNING SWITCH  .
Check the input signal from the key warning switch to the body integrated unit using the Subaru Select Monitor.
  1. Prepare the Subaru Select Monitor kit.
  2. On the "System Selection Menu", select {Integ. unit mode}.
  3. Select the {Current Data Display & Save}.
  4. Check the input signal to the body integrated unit by operating the ignition switch.
Is the normal input signal displayed when the key is inserted in/removed from the ignition switch? The key warning switch is OK. Go to step .
2 CHECK FUSE  .
Remove and visually check the fuse No. 14 (in the main fuse box).
Is the fuse blown out? Replace the fuse with a new part. Go to step .
3 CHECK KEY WARNING SWITCH CIRCUIT  .
  1. Disconnect the harness connector of body integrated unit.
  2. Insert the key into ignition switch. (LOCK position)
  3. Measure the voltage between harness connector terminal and chassis ground.

Connector & terminal 
(B279) No. 2 (+) - Chassis ground (-): 
Is the voltage 10 V or more? Go to step . Go to step .
4 CHECK KEY WARNING SWITCH CIRCUIT  .
  1. Remove the key from ignition switch.
  2. Measure the voltage between harness connector terminal and chassis ground.

Connector & terminal 
(B279) No. 2 (+) - Chassis ground (-): 
Is the voltage 0 V? Replace the body integrated unit. Refer to BODY INTEGRATED UNIT . Go to step .
5 CHECK KEY WARNING SWITCH  .
  1. Disconnect the key warning switch harness connector.
  2. Insert the key into ignition switch. (LOCK position)
  3. Measure the resistance between key warning switch terminals.

Connector & terminal 
(B350) No. 3 - No. 4: 
Is the resistance less than 1 Ω? Go to step . Replace the key warning switch.
6 CHECK KEY WARNING SWITCH  .
  1. Remove the key from ignition switch.
  2. Measure the resistance between key warning switch terminals.

Connector & terminal 
(B350) No. 3 - No. 4: 
Is the resistance 1 MΩ or more? Check the following:
  • Harness for open circuits and shorts between the key warning switch and fuse
  • Harness for open or short between the body integrated unit and key warning switch
Replace the key warning switch.