Circuit Description
The turbocharger wastegate is a vacuum actuated valve which is used in order to control the exhaust gas heat which is sent to the turbo. The wastegate pulse width modulated (PWM) solenoid meters the vacuum level at the wastegate valve actuator as commanded by the powertrain control module (PCM). When the PCM is commanding the wastegate solenoid ON, the voltage potential of the circuit will be low, near 0 volts. When the PCM is commanding the wastegate solenoid OFF, the voltage potential of the circuit will be high, near the battery voltage. The primary function of the PCM in this circuit is to supply the ground for the wastegate solenoid.
Conditions for Running the DTC
The PCM requested the wastegate solenoid ON, test 1.
or
The PCM requested the wastegate solenoid OFF, test 2.
Conditions for Setting the DTC
| • | The voltage on the wastegate solenoid control circuit is high, near the battery voltage, for test 1. |
| • | Two consecutive faults have been detected. |
| • | The conditions were met for 2 seconds. |
or
| • | The voltage on the Wastegate solenoid control circuit is low, near 0 volts, for test 2. |
| • | Two consecutive faults have been detected. |
| • | The conditions met for 2 seconds. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
This diagnostic will set when the control circuit does not follow the PCM command. When the solenoid is requested ON, the voltage will drop. When the solenoid is OFF, the ignition voltage will be present. The scan tool has a 5 second ON time abort. The wastegate solenoid can be commanded ON for as many times as needed, in 5 second intervals. DTC P0236 may possibly set along with DTC P1656. This diagnostic can be checked during key up. The engine will not respond to the scan tool commands at the idle. The engine is unable to achieve the boost pressures that are more than barometric pressure (BARO) at idle. The engine will also not respond to the scan tool commands at any engine speed which is more than the idle. The PCM control abort in order to prevent the engine damage.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step will determine if this DTC is a current or an intermittent.
-
This check can detect a partially shorted coil which would cause an excessive current flow. Leaving the circuit energized for 2 minutes allows the coil to warm up. When warm, the coil may open, the amps drop to zero, or short an amp drawn more than 0.75 amp.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 |
Important: Before clearing the DTCs, use the scan tool Capture Info to save the Freeze Frame/Failure Records for reference. The data in the control module is deleted once the Clear Info function is used. Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
Important: Ensure that both the ON and OFF states are commanded. Repeat the commands as many times as necessary. This step will determine if this DTC is a current or an intermittent. Does the solenoid turn ON and OFF (audible click) with each command? | -- | Go to Step 3 | Go to Step 5 | |
Is the current draw less than the specified value, but not zero? | 0.75 A | Go to Step 8 | Go to Step 4 | |
4 |
Does the DMM display an infinite resistance? | -- | Go to Step 13 | Go to Step 10 |
5 |
Does the J 35616-200 turn ON and OFF with each command? | -- | Go to Step 9 | Go to Step 6 |
6 |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 12 |
7 |
Does the solenoid operate? | -- | Go to Step 11 | Go to Step 10 |
8 | The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If any additional DTCs are stored, refer to the applicable DTC tables first. Are there any additional DTCs stored? | -- | Go to Diagnostic Aids | |
9 | Check for a poor connection at the wastegate solenoid and replace the terminal if necessary. Refer to Wiring Repairs in Wiring Systems. Did you perform a repair? | -- | Go to Step 15 | Go to Step 13 |
10 | Repair the wastegate solenoid control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 15 | -- |
11 | Check for a poor connection at the PCM wastegate control circuit. Repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you perform a repair? | -- | Go to Step 15 | Go to Step 14 |
12 | Repair the open in the ignition feed circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 15 | -- |
13 | Replace the wastegate solenoid. Refer to Wastegate Solenoid Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- |
14 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- |
15 |
Does the scan tool indicate the diagnostic passed? | -- | Go to Step 16 | Go to Step 2 |
16 | Does the scan tool display any additional undiagnosed DTCs? | -- | System OK | |
