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Test Preparation

  1. Manufacturer recommends using Check Harness "A" (SST 09990-01000) when using circuit tests to diagnose malfunctions. Check harness "A" is a test harness that is installed between Electronic Control Module (ECM) and ECM connectors. See Fig 1. Voltage and resistance readings are taken at check harness connectors.
    NOTE: Always check and note diagnostic trouble codes prior to disconnecting ECM connector. Disconnecting ECM connector will erase codes from memory.
  2. To install check harness "A", ensure ignition switch is in the OFF position. Disconnect ECM connector. ECM is located behind glove box.
  3. Connect check harness "A" between ECM and ECM connector. Terminal arrangement of check connector is the same as those on the ECM. Wire colors that are specified in procedures apply to ECM connectors, but may not apply to check harness connectors. Proceed to appropriate circuit test.
Fig 1: Identifying Check Harness "A"
G96E09639Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002