Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: ECM Power Source Circuit
DESCRIPTION
When the engine switch is turned on (IG), the battery voltage is applied to the IGSW terminal of the ECM.
The output signal from the MREL terminal of the ECM causes a current to flow to the coil of the semiconductor pwr integration ECU (EFI-MAIN relay), closing the contacts and supplying power to terminals +B and +B2 of the ECM.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
| 1. | CHECK SEMICONDUCTOR POWER INTEGRATION ECU (POWER SOURCE) |
| *1 | Engine Room Relay Block and Junction Block Assembly |
(a) Disconnect the semiconductor pwr integration ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| B-1 - Body ground | Always | 11 to 14 V |
| NG | .gif) | REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - SEMICONDUCTOR PWR INTEGRATION ECU) |
|
.gif)
| 2. | CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - BODY GROUND) |
(a) Disconnect the semiconductor pwr integration ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| 1D-14 - Body ground | Always | Below 1 Ω |
| 1G-5 - Body ground | Always | Below 1 Ω |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 3. | INSPECT SEMICONDUCTOR POWER INTEGRATION ECU (EFI-MAIN RELAY, IG2 RELAY) |
(a) Inspect the semiconductor pwr integration ECU (EFI-MAIN relay, IG2 relay).
Click here .gif)
| NG | | REPLACE SEMICONDUCTOR POWER INTEGRATION ECU |
|
| 4. | CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - ECM) |
(a) Disconnect the semiconductor pwr integration ECU connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| 1G-4 - A37-4 (IGSW) | Always | Below 1 Ω |
| 1G-6 - A37-46 (MREL) | Always | Below 1 Ω |
| 1G-8 - A37-2 (+B) | Always | Below 1 Ω |
| 1G-7 - A37-3 (+B2) | Always | Below 1 Ω |
| 1G-4 or A37-4 (IGSW) - Body ground and other terminals | Always | 10 kΩ or higher |
| 1G-6 or A37-46 (MREL) - Body ground and other terminals | Always | 10 kΩ or higher |
| 1G-8 or A37-2 (+B) - Body ground and other terminals | Always | 10 kΩ or higher |
| 1G-7 or A37-3 (+B2) - Body ground and other terminals | Always | 10 kΩ or higher |
HINT:
If a short is detected in any of the above circuits, there may be a malfunction in the circuit of a connected ECU.
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 5. | CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) |
(a) Disconnect the ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| D2-53 (E1) - Body ground | Always | Below 1 Ω |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 6. | CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - SEMICONDUCTOR PWR INTEGRATION ECU) |
(a) Disconnect the certification ECU (smart key ECU assembly) connector.
(b) Disconnect the semiconductor pwr integration ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| J41-17 (IG1D) - 1E-1 | Always | Below 1 Ω |
| J41-17 (IG1D) or 1E-1 - Body ground and other terminals | Always | 10 kΩ or higher |
HINT:
If a short is detected in any of the above circuits, there may be a malfunction in the circuit of a connected ECU.
| OK | | CHECK SMART ACCESS SYSTEM WITH PUSH-BUTTON START |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
Active Control Engine Mount System
DESCRIPTION LOCATION *1 No. 2 Vacuum Switching Valve Assembly (for Active Control Engine Mount) *2 Front Engine Mounting Insulator Assembly The active control engine mount system decrease ...
EVAP System
RELATED DTCS DTC No. SAE Monitoring Item Link P00FE00 P00FE EVAP vent line blocked P043E00 P043E Reference orifice clogged (built into canister pump module) P043 ...
Other materials:
Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Lighting System (w/o Automatic Headlight Beam Level Control System): Vehicle Control History
VEHICLE CONTROL HISTORY CHECK VEHICLE CONTROL HISTORY HINT:
The vehicle control history data stores the history of the reject function and system protection operations.
The number of occurrences, date and distance are stored in batches for each item.
(a) Connect the Techstream to the DLC3. ( ...
Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Safety Connect System: Telephone Sub Antenna Circuit Short to Ground (B153711,B153713)
DESCRIPTION These DTCs are stored when a malfunction occurs in the telephone and GPS antenna (for Front Side). DTC No. Detection Item DTC Detection Condition Trouble Area B153711 Telephone Sub Antenna Circuit Short to Ground Telephone antenna (sub) impedance (Ω) is lower than the m ...
Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual
- For your information
- Pictorial index
- For safety and security
- Instrument cluster
- Operation of each component
- Driving
- Lexus Display Audio system
- Interior features
- Maintenance and care
- When trouble arises
- Vehicle specifications
- For owners
Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual
0.0157