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Test QE - Key Power Check

NOTE: Perform this test only when a Code 55 is displayed in QUICK TEST.
NOTE: This test is intended to diagnose only the following circuits or components:
  • Harness circuit (KEY PWR)
  • ECA

To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault:

Fig 1: TBI Key Power Circuits
G90C14508
  1. Code 55: Check Continuity of KEY PWR Circuit  Code 55 indicates KEY PWR circuit voltage is low. Possible causes for this fault are:
    • KEY PWR circuit shorted to ground
    • Faulty ECA

    Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for corroded or damaged connector pins and repair as necessary. Install breakout box, leaving ECA disconnected. Disconnect the EEC-IV power relay or Integrated Relay Control Module (IRCM). Set DVOM on 200-ohm scale. Measure resistance between test pin No. 5 at the breakout box, and KEY PWR (KPWR) at the EEC-IV power relay vehicle harness connector. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open circuit, reconnect system components and rerun QUICK TEST PROCEDURES .

  2. Check KEY PWR Circuit For Short to Ground  Turn key off, disconnect ECA and install breakout box. Disconnect power relay or IRCM. Set DVOM on 200-k/ohm scale and measure resistance between test pin No. 5 and test pins No. 40, 46, and 60, at the breakout box. If resistance is greater than 10 k/ohms, replace ECA, reconnect components and retest system. If resistance is less than 10 k/ohms, repair short circuit. Remove breakout box, reconnect all components and repeat QUICK TEST PROCEDURES .