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Es250 Theft Deterrent Ignition Switch Circuit Test

  1. Turn ignition off. Check 15-amp ECU-IG fuse. ECU-IG fuse is located in junction block No. 1 in driver-side kick panel area. If fuse is bad, repair short in wire harness between ECU-IG fuse and theft deterrent ECU terminal B2. See Figure. If fuse is okay, go to next step.
  2. Disconnect theft deterrent ECU connectors. Theft deterrent ECU is located under dash, above glove box. Turn ignition switch to ON position. Using a DVOM, check for battery voltage between theft deterrent ECU harness terminal B2 and body ground. See Figure.
  3. If battery voltage is not present, repair open circuit in wire harness between ECU-IG fuse and harness terminal B2. If battery voltage is present, replace theft deterrent ECU, and retest system.
  4. Turn ignition off. Check 15-amp CIG fuse. CIG fuse is located in junction block No. 1 in driver-side kick panel area. If fuse is bad, repair short in wire harness between CIG fuse and theft deterrent ECU terminal A10. See Figure. If fuse is okay, go to next step.
  5. Disconnect theft deterrent ECU connectors. Theft deterrent ECU is located under dash, above glove box. Turn ignition switch to ON or ACC position. Using a DVOM, check for battery voltage between theft deterrent ECU harness terminal A10 and body ground. See Figure.
  6. If battery voltage is not present, repair open circuit in wire harness between CIG fuse and harness terminal A10. If battery voltage is present, replace theft deterrent ECU, and retest system.
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