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Home >> Suzuki >> 2005 >> Verona EX >> Repair and Diagnosis >> Body & Frame >> Glass/Windows/Mirrors >> Diagnostic Information and Procedures >> DTC 21 Rear Defroster Switch Error >> DTC Troubleshooting
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DTC Troubleshooting

DTC 21 TROUBLESHOOTING

Step Action Value(s) Yes No
1
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the rear defrost switch parameter in the ISU Miscellaneous Inputs data list.

Does the scan tool display OFF?		 - Go to Step 2. Go to Step 5.
2
  1. Activate the defogger switch.
    NOTE: The rear defrost switch parameter is a momentary display. Observe the scan tool carefully.
  2. With a scan tool, observe the rear defrost switch parameter.

Does the rear defrost switch parameter change state?		 - Go to Step 12. Go to Step 3.
3
  1. Turn OFF the ignition.
  2. Inspect the 30 A ISU Defroster Fuse F.

Is the fuse open?		 - Go to Step 4. Go to Step 7.
4
  1. Repair short to ground on the ISU voltage output circuits to the rear window and heated mirrors.
  2. Replace the 30 A ISU Defroster Fuse F.

Is the repair complete?		 - Go to Step 12. -
5
  1. Turn OFF the ignition.
  2. Disconnect the defogger switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the rear defrost switch parameter.

Does the scan tool display OFF?		 - Go to Step 9. Go to Step 6.
6 Test the signal circuit of the defogger switch for a short to ground.
Did you find and correct the condition?		 - Go to Step 12. Go to Step 7.
7 Test the signal circuit of the defogger switch for a short to voltage.
Did you find and correct the condition?		 - Go to Step 12. Go to Step 10.
8 Inspect for poor connections at the harness connector of the intelligent switching unit (ISU).
Did you find and correct the condition?		 - Go to Step 12. Go to Step 10.
9 Inspect for poor connections at the harness connector of the defogger switch.
Did you find and correct the condition?		 - Go to Step 12. Go to Step 10.
10
NOTE: Perform the program procedure for the ISU.
Did you complete the replacement?		 - Go to Step 12. -
11 Replace the defogger switch.
Did you complete the replacement?		 - Go to Step 12. -
12
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?		 - Go to Step 1. System OK
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