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Home >> Jeep >> 1996 >> Grand Cherokee Limited, 5.2 Y >> Repair and Diagnosis >> External Pages >> Different car >> Section 4 (Engine Controls - Tests W/Codes - 3.0L) >> Diagnostic Charts >> Test TC-4A - No Change In Map From Start To Run (DTC 13)

Test TC-4A - No Change In Map From Start To Run (DTC 13)

WARNING: This page is about a different car, the 1994 Plymouth Sundance, 1994 Plymouth Acclaim, 1994 Dodge Spirit, 1994 Dodge Shadow, and 1994 Chrysler LeBaron. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit and connector terminal identification, see CONNECTOR IDENTIFICATION DIRECTORY  . For wiring diagrams, see WIRING DIAGRAMS  .
  1. Turn ignition on. Using DRB, erase trouble codes. Start engine and let idle for 30 seconds. Using DRB, read trouble codes. If DRB displays NO CHANGE IN MAP FROM START TO RUN, go to step 8). If DRB does not display NO CHANGE IN MAP FROM START TO RUN, go to next step.
  2. With engine still running, using DRB set engine speed to 1500 RPM. Using DRB, read MAP sensor voltage value. While monitoring MAP sensor voltage, wiggle wiring from MAP sensor to Powertrain Control Module (PCM).
  3. If engine stalls or MAP sensor voltage becomes erratic, repair wiring or connector defect between MAP sensor and PCM. Perform TEST VER-2  . If engine does not stall or MAP sensor voltage does not becomes erratic, go to next step.
  4. Using DRB, read MAP sensor vacuum value. Snap throttle open and closed. If vacuum drops rapidly to zero in. Hg, go to next step. If vacuum does not drop rapidly to zero in. Hg, go to step 7).
  5. At this time, condition required to set trouble code is not present. NO CHANGE IN MAP FROM START TO RUN trouble code sets if too small a difference is seen between barometric pressure at key on and manifold vacuum for 1.72 seconds. Possible causes are: restricted or leaking vacuum/pressure hose to MAP sensor, ice in sensor or passage, failed MAP sensor or PCM failure. Go to next step.
  6. Inspect all related wiring and connectors. Repair as necessary. Perform TEST VER-2. If wiring and connectors are okay, see INACTIVE TROUBLE CODE CONDITION  in this article. Perform TEST VER-2.
  7. Remove MAP sensor vacuum line and check for restriction. If a restriction is present, remove restriction and reinstall MAP sensor vacuum line. Perform TEST VER-2. If restriction is not present, replace MAP sensor. Perform TEST VER-2.
  8. Turn engine off. Connect a vacuum gauge into vacuum hose to MAP sensor. Start engine and let idle. Read vacuum gauge reading. If vacuum gauge indicates zero in. Hg at idle, repair vacuum signal to MAP sensor. If vacuum gauge does not indicate zero in. Hg at idle, go to next step.
  9. While monitoring vacuum gauge, snap throttle open and closed. If vacuum does not rapidly drop to zero in. Hg, repair restricted vacuum signal. Perform TEST VER-2  .
  10. If vacuum rapidly drops to zero in. Hg, turn ignition off. Disconnect MAP sensor connector. Turn ignition on. Place DRB in voltmeter mode. Using DRB, check voltage of MAP sensor connector Violet/White wire.
  11. If voltage is less than 4 volts, repair open or short in Violet/White wire. Perform TEST VER-2. If voltage is more than 4 volts, replace MAP sensor. Perform TEST VER-2.
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