Checking the Boost Pressure Servo Motor
CHECKING THE BOOST PRESSURE SERVO MOTOR
For a complete wiring diagram Refer to the Wiring Information Electrical Diagrams Electrical Diagrams
1. CHECKING THE BOOST PRESSURE SERVO MOTOR OPERATION
NOTE: The engine temperature must be above 160°F for this test to be valid.
NOTE: Engine must be idling in park between 600 to 650 rpm.
1. Turn the ignition off.
2. Wait 30 seconds.
3. While standing in front of the vehicle, observe the position of the Boost Pressure Servo Motor armature.
NOTE: The armature should be in the 3 o'clock position with the ignition off (armature in rest position).
4. With the scan tool, actuate the Boost Pressure Servo Motor to 0%, then to 100% while monitoring the movement of the Boost Pressure Servo Motor armature.
NOTE: The Boost Pressure Servo Motor actuation will only occur for 30 seconds then actuation will stop automatically. Any readings. observations or measurements must be taken within 30 seconds of beginning of actuation.
NOTE: The armature should move 90°from the 2 o'clock position to the 5 o'clock position.
5. Repeat this actuation several times to ensure smooth consistent armature travel.
Is the Boost Pressure Servo Motor operating from the 2 o'clock (0%) to the 5 o'clock (100%) position during actuation as described ?
Yes
- Boost Pressure Servo Motor is operating correctly. Test Complete.
No
- Go To 2
2. CHECK FOR BOOST PRESSURE SERVO MOTOR LINKAGE PROBLEM
1. Turn the ignition off.
2. Disconnect the linkage from the Boost Pressure Servo Motor and inspect the linkage for foreign debris, binding or damage that could cause restricted movement.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test.Verification Tests
No
- Go to 3
3. CHECK FOR INTAKE AND EXHAUST SYSTEM RESTRICTIONS
1. Turn the ignition off.
2. Inspect the exhaust system for damaged components that could cause exhaust flow blockage.
3. Inspect all air intake, crankcase vent and turbocharger related hoses/tubes and connections for damage, air leaks or blockage.
4. Inspect the air filter for excessive dirt, soiling or other problems that may cause restricted air flow.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test.Verification Tests
No
- Go to 4
4. (A15) FUSED ASD RELAY OUTPUT CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the Boost Pressure Servo Motor harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the Fused (A15) ASD Relay Output circuit at the Boost Pressure Servo Motor harness connector.
Is the test light on?
Yes
- Go To 5
No
- Repair the Fused (A15) ASD Relay Output circuit for an open.
- Perform the ECM Verification Test.Verification Tests
5. (Z42) BOOST PRESSURE SERVO MOTOR GROUND CIRCUIT OPEN
1. Turn the ignition off.
2. Using a 12-volt test light connected to 12-volts, check the (Z42) Boost Pressure Servo Motor Ground circuit at the Boost Pressure Servo Motor harness connector.
Is the test light on?
Yes
- Replace the Boost Pressure Servo Motor.
No
- Repair the (Z42) Boost Pressure Servo Motor Ground circuit for an open.
- Perform the ECM Verification Test.Verification Tests