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

WARNING: This page is about a different car, the 1995 Dodge Ram Wagon, 1995 Dodge Ram Van, 1995 Dodge Pickup, and 1995 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn ignition on. Using scan tool, read DTCs. If scan tool displays MAP SENSOR VOLTAGE TOO LOW, go to TEST TC-5A. If scan tool does not display MAP SENSOR VOLTAGE TOO LOW, using scan tool, erase DTCs. Start engine, and allow it to idle for 30 seconds. Using scan tool, read DTCs. If scan tool displays NO CHANGE IN MAP FROM START TO RUN, go to step 8).
  2. If scan tool does not display NO CHANGE IN MAP FROM START TO RUN with engine still running, set engine speed to 1500 RPM using scan tool. Observe scan tool Manifold Absolute Pressure (MAP) sensor voltage while wiggling wiring harness from MAP sensor to Powertrain Control Module (PCM).
  3. If engine stalls or voltage becomes erratic, repair defective wiring harness or connector between MAP sensor and PCM. Perform TEST VER-2. Using scan tool, stop actuation test. Observe scan tool display and snap throttle open and closed.
  4. If vacuum did not drop rapidly to less than one in. Hg, go to step 7). If vacuum dropped rapidly to less than one in. Hg, condition required to set DTC is not present at this time.
  5. NO CHANGE IN MAP FROM START TO RUN DTC sets if too small a difference is seen between barometric pressure at key on and manifold vacuum after start-up.
  6. Possible causes are restricted or leaking passage to MAP sensor, ice in sensor or passage, and failed sensor. Test is complete. Perform TEST VER-2.
  7. Remove and inspect MAP sensor vacuum connector. Repair restriction or open in connector as necessary. Perform TEST VER-2. If connector is okay, replace MAP sensor. Perform TEST VER-2.
  8. Turn engine off. Install a vacuum gauge into Manifold Absolute Pressure (MAP) sensor vacuum supply. Start engine. Operate engine at idle and read vacuum gauge. If reading is zero at idle, repair vacuum signal to MAP sensor. Perform TEST VER-2. If reading is not zero, observe vacuum gauge and snap throttle open and closed.
  9. If vacuum did not drop rapidly to less than one in. Hg, repair restricted vacuum signal. Perform TEST VER-2. If vacuum dropped rapidly to less than one in. Hg, turn ignition off. Disconnect and inspect MAP sensor connector. Repair as necessary. Turn ignition on.
  10. Using scan tool in voltmeter mode, check voltage on MAP sensor connector, 5-volt power supply circuit (Violet/White wire). If voltage is less than 4 volts, repair Violet/White wire. Perform TEST VER-2. If voltage is more than 4 volts, replace MAP sensor. Perform TEST VER-2.
  11. Using scan tool, erase DTCs. Start engine. Allow engine to idle for 30 seconds. With engine running, use scan tool to read DTCs. If scan tool does not display NO CHANGE IN MAP FROM START TO RUN, go to step 14).
  12. If scan tool displays NO CHANGE IN MAP FROM START TO RUN, turn ignition off. Disconnect Manifold Absolute Pressure (MAP) sensor connector. Turn ignition on. Using scan tool in voltmeter mode, check voltage on MAP sensor connector, 5-volt supply circuit (Violet/White wire).
  13. 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, remove MAP sensor vacuum hose. Inspect condition of MAP sensor vacuum hose. If MAP sensor vacuum hose is restricted or open, replace vacuum hose as necessary. Perform TEST VER-2. If MAP sensor vacuum hose is okay, replace MAP sensor. Perform TEST VER-2.
  14. Using scan tool, set engine speed to 1500 RPM. With engine running at 1500 RPM, read scan tool MAP sensor voltage. While monitoring MAP sensor voltage, wiggle MAP sensor connector and wiring harness.
  15. If engine stalled or MAP sensor voltage became erratic, inspect all related wiring and connectors, and repair as necessary. Perform TEST VER-2. If engine did not stall and MAP sensor voltage did not become erratic, snap throttle open and closed while monitoring scan tool.
  16. If engine vacuum did not rapidly drop to less than one in. Hg, go to step 18). If engine vacuum rapidly dropped to less than one in. Hg, condition required to set DTC is not present at this time. Go to next step.
  17. NO CHANGE IN MAP FROM START TO RUN DTC sets if too small a difference is seen between barometric pressure at key on and manifold vacuum after engine start. Possible causes are: restricted or leaking vacuum/pressure hose to MAP sensor, ice in MAP sensor or passage, or MAP sensor failure. Perform TEST VER-2.
  18. Remove MAP sensor vacuum hose. Inspect condition of MAP sensor vacuum hose. If vacuum hose is restricted or open, replace vacuum hose as necessary. Perform TEST VER-2. If vacuum hose is okay, replace MAP sensor. Perform TEST VER-2.
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