1991 Subaru XT AutomaticFACTORY OEM SERVICE PROCEDURE

Ignition Coil Resistance Check: Legacy

  1. Disconnect 3-wire connector from ignition coil assembly. Using an ohmmeter, check resistance between terminals No. 1 and 2. See Fig 1 . This tests primary resistance of one coil.
  2. Check resistance between terminals No. 2 and 3. This tests primary resistance of other coil. If resistance is not approximately 0.7 ohm for each coil, replace ignition coil assembly.
  3. To test secondary resistance, connect one ohmmeter lead to secondary tower at one end of coil. Connect remaining ohmmeter lead to secondary tower at opposite end of same coil. Repeat test for other coil.
  4. If resistance of each coil is not approximately 13,800 ohms (Hitachi brand coil) or 21,000 ohms (Diamond brand coil), replace ignition coil assembly.
Fig 1: Legacy Ignition Coil Connector Terminal ID
G90F17389Courtesy of SUBARU OF AMERICA, INC.
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