0327721 JOHNSON HOSE, Indicator

Table 1
Diagnostic Codes Table
Code Conditions which Generate this Code System Response
526-5 Turbo Wastegate Drive : Current Below Normal The circuit driver for the electrohydraulic actuator's solenoid is energized. The Electronic Control Module (ECM) detects no current from the actuator or a current that is less than the normal level. The shutdown output is activated. The code is logged.
The engine is shut down.
526-6 Turbo Wastegate Drive : Current Above Normal The circuit driver for the electrohydraulic actuator's solenoid is energized. The ECM detects a current from the actuator that is greater than the normal level. The ECM controls the wastegate actuator by adjusting the current flow through the actuator's solenoid.The diagnostic code is probably caused by a problem with an electrical connector or with the wiring. The next likely cause is a problem inside the actuator solenoid. The least likely cause is a problem with the ECM.Logged diagnostic codes provide a historical record. Before you begin this procedure, use Caterpillar Electronic Technician (ET) to print the logged codes to a file.This troubleshooting procedure may generate additional diagnostic codes. Keep your mind on correcting the cause of the original diagnostic code. Clear the diagnostic codes after the problem is resolved.
Illustration 1 g01444497
Schematic of the circuit for the wastegate actuator
Test Step 1. Inspect the Electrical Connectors and WiringNote: This step is important for troubleshooting a problem with instability.
Illustration 2 g01431198
Terminal Box
(1) ECM connector J2/P2
(2) ECM connector J1/P1
(3) 16 amp circuit breaker
(4) Connectors J3/P3 for the customer's connector
(5) Connectors J4/P4 for the optional control panel (if equipped) or for a customer's connector
(6) J5/P5 connectors for the harness
(7) J6/P6 connectors for the harness
Turn the engine control switch to the OFF position. Switch the 16 amp circuit breaker for the ECM OFF. Note: For the following steps, refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01444485
P2 ECM terminals that are used by the solenoid for the wastegate on in-line engines and vee engines
(P2-8) Wastegate actuator's circuit driver
(P2-9) Return
Illustration 4 g01444489
Terminal locations on the P5 connector that are used by the solenoid for the wastegate on vee engines
(P5-39) Return
(P5-47) Wastegate actuator's circuit driver
Illustration 5 g01444487
Terminal locations on the P6 connector that are used by the solenoid for the wastegate on in-line engines
(P6-13) Return
(P6-23) Wastegate actuator's circuit driver
Illustration 6 g01444582
Typical view of the wastegate that is mounted on a vee engine
(8) Solenoid for the wastegate actuator
(9) Solenoid's connector
(A) Wastegate actuator's circuit driver
(B) Return
Illustration 7 g01444494
Typical view of the wastegate that is mounted on an in-line engine
(10) Wastegate actuator
(AA) Connectors for the wastegate actuator
(A) Wastegate actuator's circuit driver
(B) Return
Thoroughly inspect each of the following connectors:
ECM J2/P2 connectors
J5/P5 connectors on the terminal box
J6/P6 connectors on the terminal box
Connectors for the wastegate actuator
Check the torque of the Allen head screw for the ECM connector and for the connectors on the terminal box. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Perform a 45 N (10 lb) pull test on the wires that are associated with the circuit for the wastegate actuator.
Thoroughly inspect the connectors for the wastegate actuator for moisture and for contamination. Check the harness and wiring for abrasion and for pinch points from the wastegate actuator to the ECM. Expected Result:All connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - All connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points. The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - At least one of the connectors, pins, or sockets is not connected properly. At least one connector or wire has corrosion, abrasion, and/or pinch points. The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check for Active Diagnostic Codes
Prevent fuel from entering the engine. Verify that the gas supply to the engine is OFF.
Connect Cat ET to the service tool connector.
Switch the 16 amp circuit breaker for the ECM ON.
If a 526-5 and/or 526-6 diagnostic code is logged, clear the code.
Turn the engine control switch to the START position and crank the engine. Allow a minimum of 30 seconds for the generation of any codes.
Observe the "Active Diagnostic" screen on Cat ET. Check and record any active diagnostic codes.
Determine if the problem is related to an open circuit diagnostic code (-5) or a short circuit diagnostic code (-6).
Turn the engine control switch to the STOP position. Expected Result:No diagnostic codes are active.Results: