Lost Communication with Gateway Module (Power Management1) (U1002)
- The power management control ECU will store this DTC when no signals can be received from the ECUs that have been memorized as those that are connected to the CAN No. 2 bus.
- When the power management control ECU receives a response signal from the ECUs connected to the CAN No. 2 bus, the power management control ECU recognizes and memorizes that the ECU is connected to the CAN No. 2 bus. Based on this memorized data, the power management control ECU monitors for malfunctions in the ECUs connected to the CAN No. 2 bus when communicating with those ECUs. If the power management control ECU cannot receive response signals from the ECUs that have been memorized as those connected to the CAN No. 2 bus, the power management control ECU determines that a malfunction exists.
DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
U1002 |
Power management control ECU cannot receive signals from all ECUs that have been memorized as those connected to the CAN No. 2 bus. |
|
CAUTION / NOTICE / HINT
NOTICE:
- Turn the ignition switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
- Turn the ignition switch off before inspecting CAN bus wires for a ground short.
- After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
- Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.
HINT:
- Operating the ignition switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
- Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.
CHECK CAN NO. 2 BUS WIRE
(a) Turn the ignition switch off.
(b) Measure the resistance according to the value(s) in the table below. Standard Resistance:
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(c) Disconnect the cable from the negative (-) battery terminal.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Result |
|---|---|---|---|
D69-1 (CANH) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Below 6 kΩ: CANH +B short |
D69-2 (CANL) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Below 6 kΩ: CANL +B short |
Result | Proceed to |
|---|---|
OK |
A |
Open in CAN main bus line |
B |
|
C |
| A | ![]() | REPLACE POWER MANAGEMENT CONTROL ECU |
| C | ![]() | GO TO STEP 4 |
|
CHECK FOR OPEN IN CAN NO. 2 BUS MAIN WIRE (CAN NO. 3 J/C)
(a) Disconnect the CAN No. 3 junction connector (D69). Text in Illustration
|
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(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
|---|---|---|
D69-1 (CANH) - D69-2 (CANL) |
Ignition switch off |
108 to 132 Ω |
| OK | ![]() | REPLACE CAN NO. 3 J/C |
|
CHECK FOR OPEN IN CAN NO. 2 BUS MAIN WIRE (POWER MANAGEMENT CONTROL ECU)
(a) Reconnect the CAN No. 3 junction connector (D69).
(b) Disconnect the power management control ECU connector (D43). Text in Illustration
|
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(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
|---|---|---|
D43-26 (CA2H) - D43-25 (CA2L) |
Ignition switch off |
108 to 132 Ω |
| OK | ![]() | REPLACE POWER MANAGEMENT CONTROL ECU |
| NG | ![]() | REPAIR OR REPLACE CAN NO. 2 BUS MAIN WIRE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 3 J/C) |
CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (CAN NO. 3 J/C)
(a) Disconnect the CAN No. 3 junction connector (D69). |
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*1 |
Rear view of wire harness connector (to CAN No. 3 Junction Connector) |
*2 |
Earth Terminal |
*3 |
DLC3 |
*4 |
Red |
*5 |
White |
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
D69-1 (CANH) - D69-2 (CANL) |
Ignition switch off |
108 to 132 Ω |
Inspection for open or short circuit between bus line |
D69-1 (CANH) - D1-4 (CG) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
D69-2 (CANL) - D1-4 (CG) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
D69-1 (CANH) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
D69-2 (CANL) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANL +B short |
HINT:
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.
| NG | ![]() | GO TO STEP 9 |
|
CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (AFS ECU)
(a) Reconnect the CAN No. 3 junction connector (D69).
(b) Disconnect the AFS ECU connector.
Text in Illustration *1 |
Front view of wire harness connector (to AFS ECU) |
*2 |
DLC3 |
(c) Measure the resistance of the wire harness side connectors.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
D44-12 (CANH) - D44-13 (CANL) |
Ignition switch off |
54 to 69 Ω |
Inspection for open or short circuit between bus line |
D44-12 (CANH) - D44-22 (E1) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
D44-13 (CANL) - D44-22 (E1) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
D44-12 (CANH) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
D44-13 (CANL) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANL +B short |
HINT:
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.
| OK | ![]() | REPLACE AFS ECU |
|
CHECK CAN NO. 2 BUS BRANCH WIRE (AFS ECU)
(a) Disconnect the CAN No. 3 junction connector (D70). Text in Illustration
|
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(b) Measure the resistance of the wire harness side connectors.
Text in Illustration *1 |
Front view of wire harness connector (to AFS ECU) |
*2 |
DLC3 |
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
D44-12 (CANH) - D44-13 (CANL) |
Ignition switch off |
1 MΩ or higher |
Inspection for open or short circuit between bus line |
D44-12 (CANH) - D44-22 (E1) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
D44-13 (CANL) - D44-22 (E1) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
D44-12 (CANH) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
D44-13 (CANL) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANL +B short |
HINT:
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.
| NG | ![]() | REPAIR OR REPLACE CAN NO. 2 BUS BRANCH WIRE OR CONNECTOR (AFS ECU - CAN NO. 3 J/C) |
|
CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (CLEARANCE WARNING ECU ASSEMBLY)
(a) Disconnect the clearance warning ECU assembly connector.
Text in Illustration *1 |
Front view of wire harness connector (to Clearance Warning ECU Assembly) |
*2 |
DLC3 |
(b) Measure the resistance of the wire harness side connectors.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
D79-17 (R1) - D79-18 (R2) |
Ignition switch off |
54 to 69 Ω |
Inspection for open or short circuit between bus line |
D79-17 (R1) - D79-30 (E) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
D79-18 (R2) - D79-30 (E) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
D79-17 (R1) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
D79-18 (R2) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANL +B short |
HINT:
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.
| OK | ![]() | REPLACE CLEARANCE WARNING ECU ASSEMBLY |
|
CHECK CAN NO. 2 BUS BRANCH WIRE (CLEARANCE WARNING ECU ASSEMBLY)
(a) Disconnect the CAN No. 3 junction connector (D81). Text in Illustration
|
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(b) Measure the resistance of the wire harness side connectors.
Text in Illustration *1 |
Front view of wire harness connector (to Clearance Warning ECU Assembly) |
*2 |
DLC3 |
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
D79-17 (R1) - D79-18 (R2) |
Ignition switch off |
1 MΩ or higher |
Inspection for open or short circuit between bus line |
D79-17 (R1) - D79-30 (E) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
D79-18 (R2) - D79-30 (E) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
D79-17 (R1) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
D79-18 (R2) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANL +B short |
HINT:
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.
| OK | ![]() | REPLACE CAN NO. 3 J/C |
| NG | ![]() | REPAIR OR REPLACE CAN NO. 2 BUS BRANCH WIRE OR CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - CAN NO. 3 J/C) |
CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (POWER MANAGEMENT CONTROL ECU)
(a) Reconnect the CAN No. 3 junction connector (D69).
(b) Disconnect the power management control ECU connector. Text in Illustration
|
![]() |
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
D43-26 (CA2H) - D43-25 (CA2L) |
Ignition switch off |
108 to 132 Ω |
Inspection for open or short circuit between bus line |
D43-26 (CA2H) - D43-6 (GND) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
D43-25 (CA2L) - D43-6 (GND) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
D43-26 (CA2H) - D43-1 (AM22) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
D43-25 (CA2L) - D43-1 (AM22) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANL +B short |
HINT:
It is only necessary to perform the inspection in the above table for the result (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.
| OK | ![]() | REPLACE POWER MANAGEMENT CONTROL ECU |
| NG | ![]() | REPAIR OR REPLACE CAN NO. 2 BUS MAIN WIRE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 3 J/C) |
Test yourself
A quick Toyota Venza quiz: every answer comes with an explanation and a link to the manual page.

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