DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK THAT MIL IS ILLUMINATED
CHECK WHETHER MIL TURNS OFF
CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS)
CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
CHECK THAT ENGINE STARTS
CHECK HARNESS AND CONNECTOR (COMBINATION METER - BODY GROUND)
CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
DESCRIPTION
The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunction detected by the ECM. When the ignition switch is turned to ON, power is supplied to the MIL circuit, and the ECM provides the circuit ground which illuminates the MIL.The MIL operation can be checked visually: When the ignition switch is turned to ON, the MIL should be illuminated and should then turn off after engine is started. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the Techstream.
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.CHECK THAT MIL IS ILLUMINATED |
Turn the ignition switch to ON.
Check the illumination of the MIL.
- Result:
Condition
| Proceed to
|
MIL remains illuminated (Even after engine is started, MIL still remains illuminated)
| A
|
MIL remains off (Does not illuminate at all)
| B
|
MIL illuminates, but turns off after engine is started
| C
|
| 2.CHECK WHETHER MIL TURNS OFF |
Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Check if any DTCs have been stored. Note down any DTCs.
Clear DTCs (COROLLA_ZRE142 RM000000PDK0ZAX.html).
Check if the MIL goes off.
- OK:
- MIL goes off.
| 3.CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS) |
Disconnect the A50 ECM connector.
Turn the ignition switch to ON.
Check that the MIL is not illuminated.
- OK:
- MIL is not illuminated.
Reconnect the ECM connector.
| 4.CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) |
Disconnect the combination meter connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Short):
Tester Connection
| Condition
| Specified Condition
|
E46-20 (EFI) or A50-24 (W) - Body ground
| Always
| 10 kΩ or higher
|
Reconnect the combination meter connector.
Reconnect the ECM connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER - ECM) |
|
|
| 5.CHECK THAT ENGINE STARTS |
Turn the ignition switch to ON.
Start the engine.
- Result:
Result
| Proceed to
|
Engine starts
| A
|
Engine does not start*
| B
|
- HINT:
- *: The Techstream cannot communicate with the ECM.
| 6.CHECK HARNESS AND CONNECTOR (COMBINATION METER - BODY GROUND) |
Disconnect the ECM connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection
| Switch Condition
| Specified Condition
|
A50-24 (W) - Body ground
| Ignition switch ON
| 11 to 14 V
|
Reconnect the ECM connector.
| 7.CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM) |
Disconnect the combination meter connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
Tester Connection
| Condition
| Specified Condition
|
E46-20 (EFI) - A50-24 (W)
| Always
| Below 1 Ω
|
Reconnect the ECM connector.
Reconnect the combination meter connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER - ECM) |
|
|
