Test TC-184A - Leak Detection Pump Switch Or Mechanical Fault

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION Directory. For wiring diagram, see WIRING DIAGRAMS - NON-TURBO article.

Start engine and allow to idle. Using scan tool, read Leak Detection Pump (LDP) switch state. Using scan tool, actuate LDP solenoid. With scan tool actuating LDP solenoid, observe LDP switch state.
If scan tool indicates LDP switch state toggled, go to next step. If scan tool does not indicate LDP switch state toggled, go to step 6).
Using scan tool, stop actuation of LDP solenoid. Condition to set trouble code is not present at this time. LEAK DETECTION PUMP SOLENOID CIRCUIT DTC sets if solenoid state does not change when solenoid is energized. Possible causes are: open or shorted LDP switch sense circuit, LDP switch failure or open fused ignition switch output circuit. Go to next step.
Inspect all related wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, go to next step. If related wiring and connectors were repaired, perform TEST VER-5A.
Using scan tool, actuate LDP solenoid. While monitoring LDP switch state, wiggle wiring harness from LDP solenoid to PCM connector. If LDP switch state stopped toggling when wiggling wiring harness, repair wiring harness as necessary where wiggling caused problem to appear. Perform TEST VER-5A. If LDP switch state did not stop toggling when wiggling wiring harness, see INACTIVE TROUBLE CODE CONDITION. Test is complete. Perform TEST VER-5A.

Turn ignition off. Disconnect vacuum supply line from LDP solenoid. See LDP SOLENOID LOCATION table. Go to next step.

LDP SOLENOID LOCATION

Application	Location
F24S Body	Behind Right Front Wheel Splash Shield

Install a vacuum gauge to LDP vacuum supply hose. Start engine and observe vacuum gauge. If vacuum gauge indicates to within one in. Hg of engine vacuum, go to next step. If vacuum gauge does not indicate to within one in. Hg of engine vacuum, repair leak or obstruction in LDP solenoid vacuum supply hose. Perform TEST VER-5A.

Turn ignition off. Disconnect LDP solenoid connector. Turn ignition on. Using a voltmeter, check voltage of fused ignition switch output circuit at LDP solenoid connector. See LDP CONNECTOR WIRE IDENTIFICATION table. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open fused ignition switch output circuit. Perform TEST VER-5A.

LDP CONNECTOR WIRE IDENTIFICATION

Application	Wire Color
LDP Fused Ignition Switch Output Circuit	Black/White
LDP Solenoid Control Circuit	Red/Yellow

Turn ignition off. Disconnect Powertrain Control Module (PCM) connector. Using an ohmmeter, check resistance of LDP switch sense circuit between LDP solenoid connector and PCM connector terminal No. 72. See LDP CONNECTOR WIRE IDENTIFICATION table. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open LDP switch sense circuit. Perform TEST VER-5A.

Using an ohmmeter, check resistance of PCM connector terminal No. 72 (LDP switch sense circuit). See PCM CONNECTOR WIRE IDENTIFICATION table. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground on LDP switch sense circuit. Perform TEST VER-5A.

PCM CONNECTOR WIRE IDENTIFICATION

Application	Wire Color
PCM Terminal No. 72 (LDP Switch Sense Circuit)	Red/Dark Blue

Reconnect LDP solenoid connector. Turn ignition on. Using a voltmeter, check voltage of PCM connector terminal No. 72 (LDP switch sense circuit). See PCM CONNECTOR WIRE IDENTIFICATION table. Using a hand vacuum pump, apply vacuum to LDP and observe voltmeter. If voltage changed, replace PCM. Perform TEST VER-5A. If voltage did not change, replace LDP. Perform TEST VER-5A.