Chevrolet Trax: Malfunction indicator lamp (MIL) Diagnosis
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
Circuit/System Description
The malfunction indicator lamp (MIL) illuminates to inform the driver that an
emission system fault has
occurred and the powertrain control system requires service. Ignition voltage is
supplied directly to the MIL.
The engine control module (ECM) turns the MIL ON by grounding the MIL control
circuit when the emission
system fault occurs. Under normal operating conditions, the MIL should be ON
only when the ignition is ON
and the engine is OFF.
Diagnostic Aids
If the condition is intermittent, move the related harnesses and connectors
while monitoring the scan tool MIL
control circuit status parameters. Perform this test with the ignition ON and
the engine OFF, and with the
engine running. The MIL control circuit status parameters change from OK or Not
Run to Malfunction if there
is a condition with a circuit or a connection.
Reference Information
Schematic Reference
- Engine Controls Schematics (Encore) , Engine Controls Schematics (Trax)
- Instrument Cluster Schematics (Encore) , Instrument Cluster
Schematics (Trax)
Connector End View Reference
WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS -
INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT
CONNECTOR END VIEWS - INDEX - TRAX
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE: Any MIL requesting DTCs that may be set should be
diagnosed first.
- Ignition ON.
- Verify the parameters listed below do not display Malfunction when
commanding the Malfunction
Indicator Lamp On and Off with a scan tool.
- The MIL Control Circuit Low Voltage Test Status
- The MIL Control Circuit Open Test Status
- The MIL Control Circuit High Voltage Test Status
- If Malfunction is displayed
Refer to Circuit/System Testing
- If Malfunction is not displayed
- Engine running.
- Verify the parameters listed below do not display Malfunction when
commanding the Malfunction
Indicator Lamp On and Off with a scan tool.
- The MIL Control Circuit Low Voltage Test Status
- The MIL Control Circuit Open Test Status
- The MIL Control Circuit High Voltage Test Status
- If Malfunction is displayed
Refer to Circuit/System Testing
- If Malfunction is not displayed
- Verify the malfunction indicator lamp turns ON and OFF when commanding
the Malfunction Indicator
Lamp On and Off with a scan tool.
- If the malfunction indicator lamp does not turn ON and OFF
Refer to Circuit/System Testing
- If the malfunction indicator lamp turns ON and OFF
- All OK.
Circuit/System Testing
- Ignition OFF.
- Disconnect the X1 harness connector at the K20 Engine Control Module.
- Ignition ON, verify the malfunction indicator lamp does not illuminate.
- If the malfunction indicator lamp illuminates
- Test for infinite resistance between the control circuit terminal X1 52
and ground.
- If less than infinite resistance, repair the short to ground in the
circuit.
- If infinite resistance, replace the P16 Instrument Cluster.
- If the malfunction indicator lamp does not illuminate
- Connect a 3 A fused jumper wire between the control circuit terminal X1
52 and ground.
- Verify the malfunction indicator lamp illuminates.
- If the malfunction indicator lamp illuminates
Replace the K20 Engine Control Module.
- If the malfunction indicator lamp does not illuminate
- Test for less than 1 V between the control circuit terminal X1 52 and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Ignition OFF.
- Test for less than 2 ohms in the control circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If less than 2 ohms.
- Ignition OFF, disconnect the harness connector at the instrument cluster.
- Ignition ON, verify a test lamp illuminates between the ignition voltage
circuit terminal 31 and ground.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF.
- Test for infinite resistance between the ignition voltage circuit and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF.
- Test for less than 2 ohms in the ignition voltage circuit end to end.
- If 2 ohms or greater, repair the open/high resistance in the circuit.
- If the test lamp illuminates
- Replace the P16 Instrument Cluster.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Instrument Cluster Replacement (Encore) , Instrument Cluster
Replacement (Trax)
- Control Module References for control module replacement, programming,
and setup
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
SEE MORE:
ABS DESCRIPTION AND OPERATION
Antilock Brake System Block Diagram
Fig. 45: Antilock Brake System Block Diagram
This vehicle is equipped with the MGH 60 Mando electronic stability control
brake system. The electronic
brake control module and the brake pressure modulator are serviced separately
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptors
D