The obd clears the readiness monitors and codes every time you turn the ignition off.

1996 MERCURY MYSTIQUE
150,000 MILES
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CED026
  • MEMBER
  • 3 POSTS
I am trying to get through emissions and it wont pass cause the obd loses its memory.
Sep 29, 2011 at 4:58 PM
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RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,110 POSTS
Check the fuses. The computer requires constant power to maintain memory.
Sep 29, 2011 at 5:10 PM
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RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,110 POSTS
The schematic I have shows constant power being drawn from the stop/brake light circuit.
Sep 29, 2011 at 5:11 PM
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CED026
  • MEMBER
  • 3 POSTS
I have checked the fuses and replaced the PCM
Sep 29, 2011 at 5:16 PM
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CED026
  • MEMBER
  • 3 POSTS
I checked the brake lights and they work off and on, seems to have a lose connection somewhere in the steering colum.
Sep 29, 2011 at 5:32 PM
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RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,110 POSTS
Check the switch. It's located on the brake pedal mount. Verify that it has constant power. Check for power on the white/light blue wire on the OBDII diagnostic connector.
Sep 29, 2011 at 5:42 PM
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