LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 33 (Engine Controls - Tests W/Codes - 3.8L) >> Self-Diagnostic Tests >> Test TC-7A - No Vehicle Speed Sensor Signal (DTC 15)

Test TC-7A - No Vehicle Speed Sensor Signal (DTC 15)

WARNING: This page is about a different car, the 1995 Plymouth Voyager, 1995 Plymouth Grand Voyager, 1995 Dodge Grand Caravan, 1995 Dodge Caravan, and 1995 Chrysler Town & Country. 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  . For wiring diagrams, see WIRING DIAGRAMS  section at the end of this article.
  1. Raise vehicle so drive wheels are free to spin. Start engine. Using scan tool, read Vehicle Speed Sensor (VSS) signal. Put transmission in any forward gear. If scan tool displays more than zero MPH, go to next step. If scan tool does not display more than zero MPH, go to step 4).
  2. Condition required to set DTC is not present at this time. NO VEHICLE SPEED SENSOR SIGNAL DTC sets if Powertrain Control Module (PCM) does not see a VSS signal at PCM terminal No. 47 (White/Orange wire) under road load conditions. Possible causes are: open or shorted VSS signal circuit (White/Orange wire), no signal from Transmission Control Module (TCM) or failed PCM. Go to next step.
  3. Inspect all related wiring and connectors, and repair as necessary. Perform TEST VER-2. If no problems are found with wiring and connectors, see INACTIVE DTC CONDITION  . Perform TEST VER-2.
  4. Using scan tool, read Electronic Automatic Transmission (EATX) DTCs. If Code(s) 50-58 is displayed, go to appropriate TRANSMISSION SERVICE & REPAIR article. If Code(s) 50-58 is not displayed, turn ignition off.
  5. Disconnect Transmission Control Module (TCM) connector. Turn ignition on. Using scan tool in voltmeter mode, check voltage on TCM connector terminal No. 58, VSS signal circuit (White/Orange wire). If voltage is more than 4 volts, go to step 9).
  6. If voltage is less than 4 volts, ensure ignition is off. Disconnect Powertrain Control Module (PCM) connector. Inspect PCM connector for damaged or pushed-out terminals. Repair as necessary. Perform TEST VER-2. If connector is okay, go to next step.
  7. Using an external ohmmeter, check resistance of signal circuit (White/Orange wire) between TCM connector terminal No. 58 and PCM connector terminal No. 47. If resistance is more than 5 ohms, repair open White/Orange wire. Perform TEST VER-2.
  8. If resistance is less than 5 ohms, using scan tool in ohmmeter mode, check resistance of PCM connector terminal No. 47, signal circuit (White/Orange wire). If resistance is less than 5 ohms, repair short to ground in White/Orange wire. Perform TEST VER-2. If resistance is more than 5 ohms, replace PCM. Perform TEST VER-2.
  9. Using scan tool, read vehicle speed. Connect a jumper wire to TCM connector terminal No. 58 (White/Orange wire). While observing scan tool display, tap other end of jumper wire to ground. If scan tool displays more than zero MPH, replace TCM. Perform TEST VER-2.
  10. If scan tool does not display more than zero MPH, turn ignition off. Disconnect Powertrain Control Module (PCM) connector. Using an external ohmmeter, check resistance of signal circuit (White/Orange wire) between TCM connector terminal No. 58 and PCM connector terminal No. 47.
  11. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-2. If resistance is more than 5 ohms, repair open White/Orange wire. Perform TEST VER-2.
scientia non olet · About LEMON Manuals