P1251-VACUUM RESERVOIR SOLENOID SHORT TO GROUND

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on and the ECM Vacuum Reservoir Solenoid command off.
Set Condition:
The ECM detects a short to ground on the Vacuum Reservoir Solenoid Control circuit.

Possible Causes

INTERMITTENT CONDITION

ASD RELAY OUTPUT CIRCUIT OPEN

VACUUM RESERVOIR SOLENOID CONTROL SHORTED TO VOLTAGE

VACUUM RESERVOIR SOLENOID CONTROL CIRCUIT SHORTED TO GROUND

VACUUM RESERVOIR SOLENOID CONTROL CIRCUIT OPEN

VACUUM RESERVOIR SOLENOID

ENGINE CONTROL MODULE

Diagnostic Test

1.CHECK FOR ACTIVE DTC

NOTE: IfINTERMITTENT CONDITIONe ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.

NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.

Did this DTC set again?

Yes

Go To2

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2.CHECKING FOR OTHER DTCS

NOTE: An open ASD power supply to the ECM will cause multiple DTC's including this DTC to set.

NOTE: Check the ECM for other DTC's. If other DTC's are set with this DTC refer to the symptom list and perform the CHECKING THE ECM POWER AND GROUND CIRCUITS test before continuing.

If the ECM power and ground circuits are functioning properly continue with this test.

Yes

Go To3

3.ASD OUTPUT CKT OPEN

Does the test light illuminate brightly?

Yes

Go To4

Repair the ASD Relay Output circuit for an open.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

4.VACUUM RESERVOIR SOLENOID CONTROL SHORTED TO VOLTAGE

Is the voltage below 1.0 volt?

Yes

Go To5

Repair the Vacuum Reservoir Solenoid Control circuit for a short to voltage.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

5.VACUUM RESERVOIR SOLENOID CONTROL CIRCUIT SHORTED TO GROUND

Is the resistance above 1000 ohms?

Yes

Go To6

Repair the Vacuum Reservoir Solenoid Control circuit for a short to ground.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

6.VACUUM RESERVOIR SOLENOID CONTROL CIRCUIT OPEN

Is the resistance below 10.0 ohms?

Yes

Go To7

Repair the Vacuum Reservoir Solenoid Control circuit for an open.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

7.VACUUM RESERVOIR SOLENOID

NOTE: Ensure the ECM and Vacuum Reservoir Solenoid harness connectors are connected.

Did this DTC set again?

Yes

Replace and program the Engine Control Module in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Replace the Vacuum Reservoir Solenoid.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).