Lexus ES: MIL Circuit
DESCRIPTION
The Malfunction Indicator Lamp (MIL) is used to indicate vehicle malfunctions detected by the ECM.
The MIL operation can be checked visually. When the engine switch is first turned on (IG), the MIL should be illuminated and should then turn off after the engine is started. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the Techstream.
WIRING DIAGRAM
PROCEDURE
| 1. | CHECK THAT MIL IS ILLUMINATED |
(a) Perform troubleshooting in accordance with the table below.
| MIL | Condition | Proceed to |
|---|---|---|
| Illuminates → Turns off | Engine switch on (IG) → engine is started | A |
| Other than above | - | B |
| A | .gif) | CHECK FOR INTERMITTENT PROBLEMS |
|
.gif)
| 2. | CHECK COMMUNICATION BETWEEN TECHSTREAM AND ECM |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Check the communication between the Techstream and ECM.
HINT:
It can be checked using the "Engine" item of the Data List.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
| B | | GO TO VC OUTPUT CIRCUIT |
|
| 3. | CHECK WHETHER DTC OUTPUT RECURS |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: System Select / Health Check.
(e) Check if any DTCs have been detected. Note down any DTCs.
| Result | Proceed to |
|---|---|
| DTCs are not output | A |
| Any DTCs is output | B |
HINT:
Check for detected DTCs output from other ECUs which relate to the MIL.
| B | | REPAIR CIRCUIT INDICATED BY OUTPUT |
|
| 4. | PERFORM ACTIVE TEST USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Combination Meter / Active Test / Check Engine Warning.
Body Electrical > Combination Meter > Active Test| Tester Display |
|---|
| Check Engine Warning |
(e) Check the status of the MIL while performing the Active Test.
| Result | Proceed to |
|---|---|
| Changes | A |
| Does not change | B |
| A | | REPLACE ECM |
.gif)
| B | | REPLACE COMBINATION METER ASSEMBLY |
READ NEXT:
Drive Start Control
DESCRIPTION The drive start control is controlled by the ECM. If the ECM determines that the shift lever and accelerator pedal are operated abnormally, engine output is restricted and, when necessary,
Rough Idling
DESCRIPTION Problem Symptom Suspected Area Trouble Area
Engine speed fluctuation due to abnormal combustion
Idle speed too low or high
Strong engine vibration due to above symptoms
Engine Difficult to Start
DESCRIPTION Problem Symptom Suspected Area Trouble Area
Engine speed fluctuation due to abnormal combustion
Idle speed too low or high
Strong engine vibration due to above symptoms
SEE MORE:
Installation
INSTALLATION PROCEDURE 1. INSTALL ACCELERATOR PEDAL ASSEMBLY (a) Engage the claw to install the accelerator pedal assembly. (b) Install the 2 bolts. Torque: 7.5 N·m {76 kgf·cm, 66 in·lbf} 2. INSTALL ACCELERATOR PEDAL PAD (a) Engage the 4 claws to install the accelerator pedal pad
Warning Notification Function Malfunction
PROCEDURE 1. CHECK PROBLEM SYMPTOM (WARNING NOTIFICATION FUNCTION) (a) Check the problem symptom. (1) Check the problem symptom of the warning notification function. Result Proceed to The multi-display screen does not show a warning message even though a warning light turns on or t
