GM Service Manual Online
For 1990-2009 cars only

Schematic Reference: Engine Controls Schematics

Circuit Description

The tank pressure control valve is operated by a vacuum signal from the EVAP tank pressure control solenoid valve. The EVAP tank pressure control solenoid vacuum valve is controlled by the powertrain control module (PCM). The PCM opens the tank pressure control valve when the engine is running and the fuel level is within a specified range. The tank pressure control valve opens in order to allow the unrestricted flow of fuel vapors from the fuel tank to the EVAP canister. The DTC P1410 diagnostic determines if there is a failure in the EVAP tank pressure control solenoid vacuum valve.

Conditions for Running the DTC

    • Engine is running at steady speed.
    • Engine is operating in Close Loop.
    • Fuel tank level is between 25 and 75%.

Conditions for Setting the DTC

Low voltage indicated in the solenoid control circuit, with the fuel level higher than a specified value, when the diagnostic runs.

Action Taken When the DTC Sets

    • The PCM illuminates the malfunction indicator lamp (MIL) after two consecutive ignition cycles in which the diagnostic runs with the fault active.
    • The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC

    • The MIL turns OFF after three consecutively passing trips without a fault present.
    • A History DTC clears after 40 consecutive warm-up cycles without a fault.
    • Use the scan tool Clear DTC Information function or disconnect the PCM battery feed in order to clear the DTC.

Diagnostic Aids

Check for faulty electrical connections to the PCM.

A malfunctioning fuel level sensor may cause a DTC P1410 to set.

An intermittent malfunction may be caused by a fault in the EVAP tank pressure control solenoid valve electrical circuits. Inspect the wiring harness and components for any of the following conditions:

    • Backed out terminals.
    • Improper mating of terminals.
    • Broken electrical connector locks.
    • Improperly formed or damaged terminals.
    • Faulty terminal to wire connections.
    • Physical damage to the wiring harness.
    • A broken wire inside the insulation.
    • Corrosion of electrical connections, splices, or terminals.

If a DTC P1410 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.

Test Description

The numbers below refer to the step numbers in the diagnostic table.

  1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

  2. This step checks the operation of the EVAP tank pressure control solenoid valve. The EVAP tank pressure control solenoid vacuum valve output control is disabled by the PCM when any DTCs are stored, when engine speed is indicated, and until the engine has reached a normal operating temperature of at least 80°C (176°F).

  3. This step checks for a stuck open or leaking EVAP tank pressure control solenoid valve.

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Remove the rear seat cushion. Refer to Seat Cushion Replacement - Rear in Seats.
  2. Disconnect the 3 cavity, fuel tank EVAP solenoid electrical connector C311.
  3. Turn ON the ignition, leaving the engine OFF.
  4. Connect a test lamp from the ignition positive voltage terminal to the EVAP tank pressure control solenoid valve control circuit terminal of connector C311 (body harness side).
  5. Observe the test lamp while commanding the EVAP tank pressure control solenoid vacuum valve ON and OFF with the scan tool.

Did the test lamp illuminate only when the solenoid was commanded ON with the scan tool?

--

Go to Step 4

Go to Step 3

3

  1. Inspect the EVAP tank pressure control solenoid valve circuit for any of the following conditions:
  2. • The ignition positive voltage circuit for an open
    • The solenoid control circuit for an open or a short
  3. Repair as necessary.

Was a repair necessary?

--

Go to Step 11

Go to Step 10

4

  1. Remove the fuel tank. Refer to Fuel Tank Replacement .
  2. Inspect the EVAP tank pressure control solenoid for faulty electrical connections.
  3. Repair as necessary.

Was a necessary?

--

Go to Step 11

Go to Step 5

5

  1. Remove the EVAP tank pressure control solenoid valve. Refer to Evaporative Emission Tank Pressure Control Solenoid Valve Replace .
  2. Measure the resistance of the EVAP tank pressure control solenoid valve with a DMM.

Is the resistance of the EVAP tank pressure control solenoid valve within the specified value?

30 to 34 ohms at 20°C (68°F)

Go to Step 6

Go to Step 9

6

Caution: Do not breathe the air through the EVAP component tubes or hoses. The fuel vapors inside the EVAP components may cause personal injury.

Blow air into side port of the EVAP tank pressure control solenoid valve.

Did the air pass through the valve and out through the port on the top of the EVAP tank pressure control solenoid valve?

--

Go to Step 9

Go to Step 7

7

  1. Apply 12 volts to the EVAP tank pressure control solenoid valve.
  2. Blow air into side port of the EVAP tank pressure control solenoid valve.

Did the air pass through the valve and out through the port on the top of the EVAP tank pressure control solenoid valve?

--

Go to Step 8

Go to Step 9

8

  1. Inspect for an open or a short in the EVAP tank pressure control solenoid valve wiring harness between the solenoid and the body harness connector C311.
  2. Repair as necessary.

Was a repair necessary?

--

Go to Step 11

Fault Not Present-Go to Diagnostic Aids

9

Replace the EVAP tank pressure control solenoid valve. Refer to Evaporative Emission Tank Pressure Control Solenoid Valve Replace .

Is the action complete?

--

Go to Step 11

--

10

Replace the PCM. Refer to Powertrain Control Module Replacement .

Is the action complete?

--

Go to Step 11

--

11

  1. Perform the scan tool Clear DTC Information function and road test the vehicle within the Freeze Frame conditions that set the DTC.
  2. Review the scan tool data and check for DTCs. The repair is complete if no DTCs are stored.DTCs.

Are any DTCs displayed on the scan tool?

--

Go to the Applicable DTC Table

System OK