GASKET 1786537 - Caterpillar

System Operation Description:This procedure covers the following diagnostic codes. These diagnostic codes indicate that an electrical problem is occurring with the wastegate control solenoid:
32-05 Turbo Wastegate Solenoid current low
32-06 Turbo Wastegate Solenoid current high
32-11 Turbo Wastegate Solenoid current mismatchIf a mechanical problem occurs with the wastegate control valve or with the wastegate valve, the following diagnostic codes will become logged:
102-01 Low Boost Pressure
102-02 Boost Pressure signal erratic
102-07 Boost Pressure not respondingThis engine utilizes a wastegate control valve that is electronically controlled in order to precisely regulate the boost pressure. The Engine Control Module (ECM) monitors the signal from the boost pressure sensor in order to determine the boost pressure in the intake manifold. The ECM uses this information and other information that is related to the current power demand and the current engine operating conditions in order to determine the optimum position of the wastegate valve at the turbocharger.The turbocharger's wastegate valve regulates the amount of exhaust gas that is allowed to bypass the turbine wheel of the turbocharger. This allows the ECM to control the speed of the turbocharger and the boost pressure.
Illustration 1 g01218457
Components for wastegate (typical right side engine view)
(1) Wastegate control solenoid
(2) Wastegate control valve
(3) Wastegate pressure line The ECM controls the current to wastegate control solenoid (1) in order to actuate wastegate control valve (2). As the wastegate control solenoid is energized, the wastegate control valve begins to regulate the flow of boost pressure through wastegate pressure line (3).
Illustration 2 g01218458
Components for wastegate (typical left side engine view)
(3) Wastegate pressure line
(4) Wastegate actuator
(5) Control rod assembly
(6) Drain orifice Boost pressure from the intake manifold is diverted through wastegate pressure line (3) to wastegate actuator (4) that is mounted on the turbocharger. The wastegate actuator contains a diaphragm that is used to actuate the control rod assembly (5) for the wastegate valve. As the pressure in the wastegate actuator builds the control rod assembly is extended. This causes the wastegate valve to open the bypass passage that is internal to the turbocharger housing. Drain orifice (6) is used to allow line pressure to escape as the actuator's diaphragm is allowed to relax.Note: Attempting to defeat the wastegate could cause the engine to be derated.Note: The ECM exercises the wastegate control valve during periods of extended engine idle. The wastegate control solenoid is energized periodically if an extended period of low engine idle is detected by the ECM. This is normal. Do not troubleshoot the wastegate solenoid for this reason.
Illustration 3 g01218459
Schematic of the circuit for the wastegate control solenoid
Note: An integral connector for the wastegate control solenoid is shown in Illustration 3. Your application may have a pigtail harness connector that is attached to the solenoid. The solenoid with the integral connector is the only service replacement part that is available at this time.Test Step 1. Check for Diagnostic Codes
Turn the keyswitch to the OFF position.
Connect Caterpillar Electronic Technician (ET) to the data link connector.
Turn the keyswitch to the ON position. Note: Wait at least 30 seconds