{Scan Tool} Fuel Injector Balance Test
WARNING: This page is about a different variant/trim than selected.
- Ignition/Vehicle - Off
- Disconnect the electrical connector: X160 Inline Harness Connector
- The component's temperature should be 19 to 21°C (66 to 70°F) while testing.
- Testing is performed on the component side of the harness connector.
- Test for 1.0 to 3.0 ohms between the test points:
- {Q17A Fuel Injector 1} Control circuit terminal 1 & Control circuit terminal 7 @ X160 Inline Harness Connector
- {Q17B Fuel Injector 2} Control circuit terminal 2 & Control circuit terminal 8@ X160 Inline Harness Connector
- {Q17C Fuel Injector 3} Control circuit terminal 3 & Control circuit terminal 9 @ X160 Inline Harness Connector
- {Q17D Fuel Injector 4} Control circuit terminal 4 & Control circuit terminal 10 @ X160 Inline Harness Connector
- If not between 1.0 and 3.0 ohms
Replace the component: Q17 Fuel Injector
- Go to next step: If between 1.0 and 3.0 ohms
- Connect the electrical connector: X160 Inline Harness Connector
- Ignition - On/Vehicle - In Service Mode
- Perform the scan tool control function: Fuel Pump Enable - On - Command the function On several times.
Verify the scan tool parameter: Fuel Pressure Sensor = 320 to 608 kPa (46 to 88 PSI)
- If not between 320 and 608 kPa (46 and 88 PSI)
Refer to: Fuel System Diagnosis
- Go to next step: If between 320 and 608 kPa (46 and 88 PSI)
- If not between 320 and 608 kPa (46 and 88 PSI)
- Engine - Idling
- Verify the scan tool parameter: Fuel Rail Pressure Sensor = 1.9 to 5.0 MPa (276 to 725 PSI)
- If not between 1.9 and 5.0 MPa (276 and 725 PSI)
- Go to next step: If between 1.9 and 5.0 MPa (276 and 725 PSI)
- Engine - Running@600 to 1, 000 RPM
- Perform the scan tool control function: Fuel Injector Balance - Cylinder 1-4 - Enable - One at a time
- Record the value - Fuel Pressure Drop - After each component test.
- Add all the recorded values, except the suspected faulty component. This is the total pressure drop.
- Perform the following steps:
- Total pressure drop÷Number of components = Average pressure drop
- Average pressure dropx 0.20 (20%) = Acceptable variance between components
Verify the difference between a single pressure drop and the average pressure drop is not greater than the acceptable variance.
- If greater than the acceptable variance
Replace the component: Q17 Fuel Injector
- Go to next step: If within the acceptable variance
- All OK.
NOTE:
This diagnostic assumes there are no circuit faults.
NOTE:
NOTE:
The fuel pump may need to be commanded On a few times in order to obtain the highest possible fuel pressure.
NOTE:
Perform the following test for all 4 components.
NOTE:
For engines with 2 cylinder banks, only measure the average pressure drop across cylinders that are on the same bank.