P2404

P2404-EVAPORATIVE EMISSION SYSTEM LEAK DETECTION PUMP CONTROL CIRCUIT/OPEN





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
With fuel level between 15% and 85%, engine off time greater than 8 hours, engine temperature below 36° C (97° F), engine running for between 2 and 10 seconds, purge valve open beyond 10%, LDP solenoid supply voltage between 6.0 and 18.0 volts, and vehicle speed below 55 km/h (34 mph). The test can also be started by a request from the service tool.

- Set Condition:
The PCM turns the EVAP Purge solenoid off to seal the EVAP system prior to starting the leak test. The PCM activates the LDP Solenoid (on/off) to apply intake manifold vacuum to one side of the Leak Detection Pump to create a pumping action. The LDP pumps up the fuel tank system to a given pressure to test for leaks. If at any time the switch does not follow the intended reaction to the pump stroke, then the code is set. Two trip fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
1. Ignition on, engine not running.
2. With a scan tool, read DTCs and record the related Freeze Frame data if any DTC(s) are present.
3. Whether or not any DTC(s) are present you will want to check the following items which may assist in repairing the customer's complaint successfully.
4. Check the vehicles repair history.
5. If the vehicle has a repair history that pertains to the customer's current complaint, review the repair.
6. Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
7. Check for any service bulletin(s) related to the customer's complaint or DTC(s).
8. If a service bulletin applies, follow the instructions per the service bulletin.

Choose the following scenario that best applies.

The service bulletin repaired the customer's complaint.

- Testing complete.

A DTC is present, no service bulletins apply, or the service bulletin didn't repair the customer's complaint.

- Go To 2

2. ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.

Is the DTC active at this time?

Yes

- Go To 3

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Checking for an Intermittent DTC.

3. LDP
1. Turn the ignition off.
2. Disconnect the LDP connector.
3. Measure the resistance between the terminals of the LDP.

Is the resistance between 29.0 and 44.0 Ohms?

Yes

- Go To 4

No

- Replace the LDP.
- Perform the PCM Verification Test. PCM Verification Test.

4. FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN
1. Ignition on, engine not running.
2. Using a 12-volt test light connected to ground, probe the Fused Ignition Switch Output circuit.

Does the test light illuminate brightly?

Yes

- Go To 5

No

- Repair the excessive resistance or short to ground in the Fused Ignition Switch Output circuit. Inspect related fuse and repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test.

5. LDP SENSE CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the C3 PCM harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Measure the resistance of the LDP SENSE circuit from the PCM harness connector to the LDP harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the open in the LDP SENSE circuit.
- Perform the PCM Verification Test. PCM Verification Test.

6. LDP SENSE CIRCUIT SHORT TO GROUND
1. Measure the resistance between ground and the LDP SENSE circuit.

Is the resistance below 100 Ohms?

Yes

- Repair the short to ground in the LDP SENSE circuit.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Go To 7

7. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Repair

- Replace and program the Powertrain Control Module. Service and Repair.
- Perform the PCM Verification Test. PCM Verification Test.