| Last Modified: 07-31-2024 | 6.11:8.1.0 | Doc ID: RM100000001H5W4 |
| Model Year Start: 2020 | Model: Corolla | Prod Date Range: [01/2019 - 09/2022] |
| Title: LIGHTING (EXT): LIGHTING SYSTEM (for HV Model): Taillight Relay Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022] | ||
|
Taillight Relay Circuit |
DESCRIPTION
The main body ECU (multiplex network body ECU) controls the operation of the TAIL relay.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
- Inspect the fuses for circuits related to this system before performing the following procedure.
-
Before replacing the main body ECU (multiplex network body ECU), refer to Registration.
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![2020 MY Corolla Corolla HV [01/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION](/t3Portal/stylegraphics/info.gif)
PROCEDURE
|
1. |
PERFORM ACTIVE TEST USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Main Body / Active Test.
(e) Perform the Active Test according to the display on the Techstream.
Body Electrical > Main Body > Active Test
|
Tester Display |
Measurement Item |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Taillight Relay |
Taillight relay |
OFF or ON |
- |
Body Electrical > Main Body > Active Test
|
Tester Display |
|---|
|
Taillight Relay |
OK:
Taillights illuminate.
| OK |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE
|
|
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2. |
CHECK HARNESS AND CONNECTOR (POWER SOURCE - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) |
(a) Disconnect the 4D instrument panel junction block assembly connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
4D-1 - Body ground |
Power switch off |
11 to 14 V |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
3. |
INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY |
|
*a |
Component without harness connected (Instrument Panel Junction Block Assembly) |
- |
- |
(a) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
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(b) Connect a positive (+) lead from the auxiliary battery to terminal 4D-1.
(c) Connect a negative (-) lead from the auxiliary battery to terminal MB-14 (TRLY).
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
4B-32 - Auxiliary battery negative (-) terminal |
Always |
11 to 14 V |
|
4A-30 - Auxiliary battery negative (-) terminal |
Always |
11 to 14 V |
| OK |
|
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)
|
| NG |
|
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
|
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