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Home >> Cadillac >> 1991 >> DeVille Base, 4D Sedan >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Pcm Flow Charts Codes E12 To E99 >> Pcm Code E15, Open Coolant Sensor Circuit >> Test Procedures

Test Procedures

NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. If coolant sensor or wiring is open, parameter P.0.4 will read -26°F (-32°C) or less. If not, sensor signal is not open. See NOTE ON INTERMITTENTS.
  2. Checks for open sensor signal circuit No. 410 from PCM to sensor connector. If parameter P.0.4 reads 298-304°F (148-151°C) with connector shorted, circuits No. 410 and No. 476 are okay.
  3. Checks for open sensor ground circuit No. 476 from sensor pin "A" to the ground splice. If shorting pin "A" to ground causes parameter P.0.4 to read 298-304°F (148-151°C), an open in circuit No. 410 from the PCM to the coolant sensor exists.
  4. Checks for PCM's ability to recognize a short to ground or low voltage on terminal E16 (coolant sensor input). If grounding terminal E16 cause parameter P.0.4 to read 298-304°F (148-151°C), then there is an open in circuit No. 410 from the PCM to the coolant sensor.
  5. Fault is at PCM connector or PCM. Before PCM is replaced, perform PFI CHART C-1, PCM REPLACEMENT CHECK.
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