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Home >> Cadillac >> 1988 >> Seville Base >> Repair and Diagnosis >> Engine Performance >> System >> DFI ECM Tests W/Codes >> ECM Chart A - Multiple Codes Stored Hard >> Chart A1
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Chart A1

If codes EO22 and EO32 are both stored hard, the cause is probably a loss of 5 volts to circuit No. 474 (5 volt reference to MAP and TPS). To verify this condition, probe the following harness terminals with a voltmeter to ground: MAP sensor harness connector pin "C" and TPS connecter pin "C".

If voltage is zero for both circuits, check circuit No. 474 for an open or short to ground. If wiring is okay, either the ECM connector or the ECM itself is faulty. If 5 volt reference signal is available on both sensors' terminals, go to the diagnostic chart for each individual code. Diagnose code EO22 first and then code EO32.