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Home >> Isuzu >> 2008 >> Ascender LS, 4WD >> Repair and Diagnosis >> Accessories & Equipment >> Memory Modules >> Configurable Customer Control System >> Diagnostic Information & Procedures >> Steering Wheel Controls Inoperative >> Circuit/System Testing
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Circuit/System Testing

IMPORTANT: It is recommended that Component Testing is performed before Circuit Testing when diagnosing steering wheel controls.
CAUTION: Refer to SIR Caution .
  1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
  2. Ignition ON, test for ignition voltage between the ignition circuit terminal 1 and ground.
    • If less than the specified value, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  3. Test for ignition voltage between the ignition circuit terminal 1 and the signal circuit terminal 6.
    • If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
    • If greater than the specified value, test the signal circuit for a short to voltage.
  4. Install a 3A fused jumper wire at the ignition circuit terminal 1 and the ignition circuit jumper terminal 2.
  5. Disconnect the harness connector at the left steering wheel control switch.
  6. Test for ignition voltage between the ignition circuit jumper terminal 1 and ground.
    • If less than the specified value, test the signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the BCM.
  7. Test for ignition voltage between the ignition circuit jumper terminal 1 and the signal circuit terminal 5.
    • If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
  8. Disconnect the harness connector X1 at the BCM.
  9. Test for infinite resistance between the signal circuit terminal B8 and ground.
    • If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
  10. If all circuits test normal, test or replace the switch.