| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000001LF5M |
| Model Year Start: 2020 | Model: GR Corolla | Prod Date Range: [09/2019 - 04/2020] |
| Title: CELLULAR COMMUNICATION: SAFETY CONNECT SYSTEM (for Sedan, Gasoline Model): B1572; Telephone Microphone Error; 2020 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 04/2020] | ||
|
DTC |
B1572 |
Telephone Microphone Error |
DESCRIPTION
This DTC is set when the DCM (Telematics Transceiver) detects a malfunction in the telephone microphone assembly circuit.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
B1572 |
Telephone Microphone Error |
Current of MCVD reaches malfunction criteria for 10 seconds while engine switch is on (IG). |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
HINT:
Before performing this diagnostic procedure, make sure to perform Health Check and confirm that the DCM/VIN registration information is correct.
Click here
![2020 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 04/2020]; CELLULAR COMMUNICATION: SAFETY CONNECT SYSTEM (for Sedan, Gasoline Model): HEALTH CHECK](/t3Portal/stylegraphics/info.gif)
PROCEDURE
|
1. |
CHECK DTC |
(a) Turn the engine switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the engine switch on (IG) and wait for 10 seconds.
(d) Turn the Techstream on.
(e) Clear the DTCs.
Body Electrical > Telematics > Clear DTCs
(f) Recheck for DTCs.
Body Electrical > Telematics > Trouble Codes
|
Result |
Proceed to |
|---|---|
|
DTC B1572 is output |
A |
|
DTC B1572 is not output |
B |
| B |
|
|
|
2. |
INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY POWER SOURCE) |
|
(a) Remove the map light assembly but do not disconnect the connectors. Click here
|
|
(b) Measure the voltage and resistance according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
T6-7 (MACC) - Body ground |
Engine switch on (ACC) |
4 to 6 V |
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
T6-5 (MCO-) - Body ground |
Always |
Below 1 Ω |
| NG |
|
|
|
3. |
CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) - MAP LIGHT ASSEMBLY) |
(a) Disconnect the I72 DCM (Telematics Transceiver) connector.
(b) Disconnect the T6 map light assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I72-34 (MCI+) - T6-6 (MCO+) |
Always |
Below 1 Ω |
|
I72-34 (MCI+) or T6-6 (MCO+) - Body ground |
Always |
10 kΩ or higher |
|
I72-35 (MCI-) - T6-5 (MCO-) |
Always |
Below 1 Ω |
|
I72-35 (MCI-) or T6-5 (MCO-) - Body ground |
Always |
10 kΩ or higher |
|
I72-32 (SGND) - Body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4. |
REPLACE TELEPHONE MICROPHONE ASSEMBLY |
(a) Replace the telephone microphone assembly with a normal one and check if the same problem occurs again.
Click here
OK:
The system returns to normal.
| OK |
|
END |
| NG |
|
|
5. |
INSPECT DCM (TELEMATICS TRANSCEIVER) (TELEPHONE MICROPHONE ASSEMBLY POWER SOURCE) |
|
(a) Remove the DCM (Telematics Transceiver) but do not disconnect the connectors. Click here
|
|
(b) Measure the voltage and resistance according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I72-33 (MCVD) - Body ground |
Engine switch on (ACC) |
4 to 6 V |
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I72-35 (MCI-) - Body ground |
Always |
Below 1 Ω |
| OK |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
6. |
REPLACE DCM (TELEMATICS TRANSCEIVER) |
(a) Replace the DCM (Telematics Transceiver).
Click here
NOTICE:
- The engine switch must be off.
- Do not swap the DCM (Telematics Transceiver) with one from another vehicle.
| NEXT |
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