1996 Isuzu Oasis LSFACTORY OEM SERVICE PROCEDURE

DTC P0108 - Map Sensor

  1. Start engine. Raise and hold engine speed to 3000 RPM with transmission in Park or Neutral, until radiator cooling fan comes on. Let engine idle. Check MAP sensor using scan tool. If MAP sensor reading is not 30.0 in. Hg or more, failure is intermittent. System is okay at this time. Check for poor connections or loose wires at 14-pin connector (on right shock tower), MAP sensor connector, and PCM connector.
  2. If MAP sensor reading is 30.0 in. Hg or more, turn ignition off. Disconnect MAP sensor connector. Install jumper wire between MAP sensor harness connector terminals No. 2 and No. 3. See Figure . Turn ignition on. Check MAP sensor using scan tool. If MAP sensor reading is not 30.0 in. Hg or more, replace MAP sensor. If MAP sensor reading is 30.0 in. Hg or more, turn ignition off.
  3. Remove jumper wire from MAP sensor connector. Turn ignition on. Measure voltage between MAP sensor connector terminals No. 1 (VCC1) and 2 (SG1). See Figure . If approximately 5 volts exists, turn ignition off and go to next step. If approximately 5 volts does not exist, repair open in SG1 circuit between PCM connector D12 and MAP sensor connector terminal No. 2. See WIRING DIAGRAMS  section.
  4. Install jumper wire between PCM connector terminals D3 (MAP) and D12 (SG1). See Figure . Turn ignition on. Check MAP sensor using scan tool. If MAP sensor reading is not 30.0 in. Hg or more, repair open in MAP circuit between MAP sensor and PCM connector terminal D3. If MAP sensor reading is 30.0 in. Hg or more, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.