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Home >> Kia >> 2002 >> Rio Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P01640: Main Relay Malfunction >> Test Procedure
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Test Procedure

  1. Turn ignition off. Located Main relay in engine compartment fuse/relay box. See Figure . Check connector terminals and test Main relay operation. See FUEL PUMP & MAIN RELAYS (RIO) under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING article. If connector terminals and/or Main relay are okay, go to next step. If connector terminals and/or Main relay are faulty, replace as necessary. Go to step  3 .
  2. Turn ignition off. Disconnect ECM harness connector "B04". See Figure . Turn ignition on. Measure voltage between ground and ECM connector terminal B04-34. Voltage should be battery voltage. If voltage is as specified. Problem is intermittent, check Main relay connector terminals and for proper connection at fuse/relay box, repair if necessary. Go to next step. If voltage is not as specified, check circuit fuses, repair open or short circuit between Main relay and ECM as necessary. See RIO in WIRING DIAGRAMS article. After repair go to next step.
  3. After repair, return vehicle to original condition. Clear codes using Hi-Scan Pro/Kia Data Pro Scan tool or equivalent. Verify repairs by driving vehicle and monitoring for pending codes. If DTC is set during test drive, follow appropriate DTC test procedure.
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