DTC P1494: LEAK DETECTION PUMP SW OR MECHANICAL FAULT Dodge Durango I

Note. For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.

Note. Leak detection pump may also be referred to as EVAP leak detection pump. Leak detection pump pressure switch operation is monitored immediately after a cold start with battery temperature of 40-90°F (4.4-32.0°C) and engine coolant temperature within 10°F (-12°C) of battery temperature. DTC may be stored in Powertrain Control Module (PCM) if state of leak detection pump switch does not change when solenoid is energized. Possible causes are: DTC does not match FREEZE FRAME DTC, leaking or restricted hose, defective leak detection pump, defective PCM, or defective connectors or wiring.

1. Turn ignition on with engine off. Using scan tool, check for DTCs. If DTC SPECIFIC GOOD TRIP counter is not displayed and equal to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter is displayed and equal to zero, go to step 7.
2. Ensure ignition is on with engine off. Using scan tool, check to see if DTC matches FREEZE FRAME DTC. If DTC matches FREEZE FRAME DTC, go to next step. If DTC does not match FREEZE FRAME DTC, perform repair procedures for FREEZE FRAME DTC and then perform «TEST VER-5»(ref-9482-S35719050532000102700000).
3. Ensure ignition is on with engine off. Using scan tool, read FREEZE FRAME data to determine when DTC was stored. Attempt to duplicate conditions recorded in FREEZE FRAME data while noting DTC SPECIFIC GOOD TRIP counter. If DTC SPECIFIC GOOD TRIP counter changes to zero, go to next step. If DTC SPECIFIC GOOD TRIP counter does not change to zero, go to step 11.
4. Start engine and allow engine to idle. Using scan tool in LEAK DETECTION PUMP TEST, press up and down arrow on scan tool to perform switch test. While monitoring leak detection pump switch state on scan tool, wiggle wiring harness and connectors between leak detection pump and PCM. Leak detection pump is located at driver's side front corner of engine compartment, just below the battery. (Схема №62) PCM is located at passenger's side front corner of engine compartment on inner fender panel. If leak detection pump switch state does not stop toggling while wiggling wiring harness and connectors, go to next step. If leak detection pump switch state stops toggling while wiggling wiring harness and connectors, shut engine off. Repair wiring or connectors between PCM and leak detection pump as necessary. Perform «TEST VER-5»(ref-9482-S35719050532000102700000).
5. Ensure engine is running. Using scan tool in LEAK DETECTION PUMP TEST, ensure leak detection pump switch is in closed position. While monitoring leak detection pump switch state on scan tool, select "1" on scan tool. If leak detection pump switch state does not toggle, shut engine off. Go to next step. If leak detection pump switch state toggles, shut engine off. Go to step 12.
6. Ensure ignition is off. Inspect wiring harness and connectors between PCM and leak detection pump. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary. Perform «TEST VER-5»(ref-9482-S35719050532000102700000).
7. Disconnect engine vacuum supply hose at leak detection pump. Connect vacuum gauge to disconnected engine vacuum supply hose at leak detection pump and at vacuum source on the engine. Start engine and note vacuum readings. If vacuum reading at engine vacuum supply hose at leak detection pump is within one in. Hg of that obtained on engine vacuum source, shut engine off. Remove vacuum gauges, reinstall engine vacuum supply hose and go to next step. If vacuum reading at engine vacuum supply hose at leak detection pump is not at least one in. Hg of that obtained on engine vacuum source, shut engine off. Remove vacuum gauges and repair leak or obstruction on engine vacuum supply hose to leak detection pump. Perform «TEST VER-5»(ref-9482-S35719050532000102700000).
8. Ensure ignition is off. Disconnect leak detection pump connector. Turn ignition on with engine off. Using scan tool in INPUTS/OUTPUTS mode, monitor leak detection pump switch state while connecting jumper wire between positive battery terminal and terminal No. 4 (Orange wire) on leak detection pump connector. If leak detection pump switch state does not change, remove jumper wire and go to next step. If leak detection pump switch state changes, replace leak detection pump. Perform «TEST VER-5»(ref-9482-S35719050532000102700000).
9. Ensure ignition is off and leak detection pump connector is still disconnected. Disconnect PCM connectors. PCM is located at passenger's side front corner of engine compartment on inner fender panel. Using ohmmeter, check resistance between terminal No. 4 (Orange wire) on leak detection pump connector and terminal No. 14 (Orange wire) on PCM connector C3. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open on Orange wire between leak detection pump and PCM. Perform «TEST VER-5»(ref-9482-S35719050532000102700000).
10. Ensure leak detection pump connector and PCM connectors are still disconnected. Using ohmmeter, check resistance between ground and terminal No. 14 (Orange wire) on PCM connector C3. If resistance is 5 ohms or more, replace PCM. Perform «TEST VER-5»(ref-9482-S35719050532000102700000). If resistance is less than 5 ohms, repair short to ground on Orange wire between leak detection pump and PCM. Perform «TEST VER-5»(ref-9482-S35719050532000102700000).
11. Start engine and allow engine to idle. Using scan tool in LEAK DETECTION PUMP TEST, press up and down arrow on scan tool to perform switch test. While monitoring leak detection pump switch state on scan tool, wiggle wiring harness and connectors between leak detection pump and PCM. Leak detection pump is located at driver's side front corner of engine compartment, just below the battery. (Схема №62) PCM is located at passenger's side front corner of engine compartment on inner fender panel. If leak detection pump switch state does not stop toggling while wiggling wiring harness and connectors, go to next step. If leak detection pump switch state stops toggling while wiggling wiring harness and connectors, repair wiring or connectors between PCM and leak detection pump as necessary. Perform «TEST VER-5»(ref-9482-S35719050532000102700000).
12. Shut engine off. Ensure ignition is off. Inspect wiring harness and connectors between PCM and leak detection pump. If no problems exist, test is complete. If any problems exist, repair wiring or connectors as necessary. Perform «TEST VER-5»(ref-9482-S35719050532000102700000).