Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Jeep >> 1998 >> Cherokee Classic, 2.5 P >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - Engine Performance >> Self-Diagnostic Tests >> Test TC-135A: No 5 Volts To Map Sensor

Test TC-135A: No 5 Volts To Map Sensor

NOTE: This test applies to AB body only. For connector terminal identification, see CONNECTOR IDENTIFICATION . For component location and wiring diagram, see WIRING DIAGRAMS article.
  1. Start engine and allow it to idle. Using scan tool, read Manifold Absolute Pressure (MAP) sensor voltage. If voltage is less than 0.2 volt, go to step 7)  . If voltage is 0.2 volt or more, go to next step.
  2. Turn engine off. Turn ignition on, engine off. Using scan tool, read MAP sensor voltage. If voltage is less than 2.35 volts, go to step 7)  . If voltage is 2.35 volts or more, go to next step.
  3. Wiggle wiring harness and connector going to MAP sensor while monitoring MAP sensor voltage. If voltage changes while wiggling wiring harness, repair wiring harness or connector as necessary and perform TEST VER-5A: ROAD TEST FOR OBD-II TROUBLE CODES . If voltage does not change while wiggling wiring harness, go to next step.
  4. Condition required to set DTC is not present at this time. MAP SENSOR VOLTAGE TOO LOW DTC sets when MAP sensor signal voltage is less than 1.13 volts with battery voltage more than 10.4 volts and engine speed at 416-3520 RPM. Possible causes are: shorted MAP sensor signal circuit, defective connections, defective MAP sensor or PCM. Go to next step.
  5. NO 5 VOLTS TO MAP SENSOR DTC sets when MAP sensor voltage is less than 2.35 volts with ignition off for 5 seconds. Possible causes are: open 5-volt supply circuit or MAP sensor failure. Go to next step.
  6. Inspect all related wiring and connectors. Repair wiring and connectors as necessary and perform TEST VER-5A: ROAD TEST FOR OBD-II TROUBLE CODES . If wiring and connectors are okay, see INACTIVE DTC CONDITION . Test is complete. Perform TEST VER-5A: ROAD TEST FOR OBD-II TROUBLE CODES .
  7. Turn engine off. Turn ignition on, engine off. Disconnect MAP sensor connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-5A: ROAD TEST FOR OBD-II TROUBLE CODES . If connector and terminals are okay, go to next step.
  8. Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Inspect connectors and terminals for damage. Repair connectors and terminals as necessary and perform TEST VER-5A: ROAD TEST FOR OBD-II TROUBLE CODES . If connectors and terminals are okay, go to next step.
  9. Using an external ohmmeter, check resistance of MAP sensor 5-volt supply circuit (Orange wire) between MAP sensor and PCM. If resistance is 5 ohms or more, repair open 5-volt supply circuit and perform TEST VER-5A: ROAD TEST FOR OBD-II TROUBLE CODES . If resistance is 5 ohms or less, replace PCM and perform TEST VER-5A: ROAD TEST FOR OBD-II TROUBLE CODES .
NOTE: A break in test sequence occurs at this point. Sequence skips from TEST TC-135A to TEST TC-138A. No tests have been omitted.
scientia non olet · About Mike's Workshop Manuals