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DTC PZ1970, Exterior Light Power Fault: Testing

  1. Turn ignition switch to OFF position. Remove parking light relay and headlight relay. Using DVOM, measure resistance between parking light relay connector terminal No. 86 and ground. If resistance is greater than 5 ohms, go to step 3). If resistance is 5 ohms or less, go to next step.
  2. Repair short to ground in exterior light power circuit between parking light relay and PZM. Turn ignition switch to ON position. Turn headlights on. Check for DTC PZ1970. If DTC PZ1970 is present, replace PZM. If DTC PZ1970 is not present, system is functioning properly.
  3. Install headlight relay. Using DVOM, measure resistance between parking light relay connector terminal No. 86 and ground. If resistance is 5 ohms or less, replace headlight relay. If resistance is greater 5 ohms, go to next step.
  4. Install parking light relay. Remove headlight relay. Using DVOM, measure resistance between headlight relay connector terminal No. 86 and ground. If resistance is 5 ohms or less, replace parking light relay. If resistance is greater than 5 ohms, replace PZM.
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