Charcoal Canister Shutoff Valve
P0446 - CHARCOAL CANISTER SHUTOFF VALVE
When Monitored and Set Condition
- When Monitored: The ignition on or engine running. Battery voltage greater than 10 volts.
- Set Condition: An improper voltage level has been detected on the Charcoal Canister Shutoff Valve Control circuit.
For a complete Powertrain Control Module Circuit Diagram, Schematics and Diagrams.
Diagnostic Test
1. PRE-DIAGNOSTIC CHECK OUT
NOTE: Always perform diagnostics with a fully charged battery.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
NOTE: Check for applicable TSBs related to the problem.
Turn the ignition on.
With the scan tool, read PCM DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Perform this procedure prior to symptom diagnosis.
Continue
- Go To 2
2. CHECK FOR CURRENT DTC
NOTE: If the PCM detects and stores a DTC, the PCM 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 a DTC.
Turn the ignition on.
With the scan tool, erase PCM DTCs.
NOTE: It maybe necessary to road test the vehicle for this DTC to set.
With the scan tool, read PCM DTCs.
Did this DTC set again?
Yes
- Go To 3
No
- Go To 8
3. CHARCOAL CANISTER SHUTOFF VALVE
NOTE: Check the Engine Control Fuse 2 in the Relay Control Module. If it is open, multiple DTCs will be set in the PCM. Determine the cause of the open fuse before continuing using the wiring diagrams/schematics as a guide.
Turn the ignition off.
Disconnect the Charcoal Canister Shutoff Valve harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Using a 12-volt test light, jumper across the Charcoal Canister Shutoff Valve harness connector.
Turn the ignition on.
Does the test light illuminate?
Yes
- Replace the Charcoal Canister Shutoff Valve. Removal.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
No
- Go To 4
4. FUSED ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN
With the ignition on.
Connect a 12-volt test light between ground and the Fused Engine Control Relay Output circuit at the Charcoal Canister Shutoff Valve harness connector.
Does the test light illuminate brightly?
Yes
- Go To 5
No
- Repair the Fused Engine Control Relay Output circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
5. CHARCOAL CANISTER SHUTOFF VALVE CONTROL CIRCUIT SHORT TO VOLTAGE
Turn the ignition off.
Disconnect the PCM C4 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Turn the ignition on.
Measure the voltage of the Charcoal Canister Shutoff Valve Control circuit at the Charcoal Canister Shutoff Valve harness connector.
Is the voltage below 1.0 volt?
Yes
- Go To 6
No
- Repair the Charcoal Canister Shutoff Valve Control circuit for a short to voltage.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
6. CHARCOAL CANISTER SHUTOFF VALVE CONTROL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the Charcoal Canister Shutoff Valve Control circuit from the Charcoal Canister Shutoff Valve harness connector to the PCM C4 harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 7
No
- Repair the Charcoal Canister Shutoff Valve Control circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
7. CHARCOAL CANISTER SHUTOFF VALVE CONTROL CIRCUIT SHORT TO GROUND.
With the ignition off.
Measure the resistance between ground and the Charcoal Canister Shutoff Valve Control circuit at the Charcoal Canister Shutoff Valve harness connector.
Is the resistance above 100 kohms?
Yes
- Replace and program the Powertrain Control Module. Powertrain Control Module - Removal.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
No
- Repair the Charcoal Canister Shutoff Valve Control circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
8. INTERMITTENT WIRING AND CONNECTORS
The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
NOTE: Check for any Technical Service Bulletins that may apply.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST - VER 2. Powertrain Verification Test
No
- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.