Lost Communication with Gateway Module (Power Management2) (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 power management bus.
- When the power management control ECU receives a response signal from the ECUs connected to the power management bus, the power management control ECU recognizes and memorizes that the ECU is connected to the power management bus. Based on this memorized data, the power management control ECU monitors for malfunctions in the ECUs connected to the power management 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 power management 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 power management 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 BUS WIRE
(a) Turn the ignition switch off.
(b) Measure the resistance according to the value(s) in the table below. Text in Illustration
Standard Resistance:
|
 |
(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 |
|---|---|---|---|
D43-12 (CA3P) - D43-1 (AM22) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Below 6 kΩ: CANH +B short |
D43-11 (CA3N) - D43-1 (AM22) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Below 6 kΩ: CANL +B short |
Result | Proceed to |
|---|---|
OK |
A |
Open circuit in CAN main bus wire |
B |
Short circuit between bus wires |
C |
|
D |
| A | .gif) | REPLACE POWER MANAGEMENT CONTROL ECU |
| C | | GO TO STEP 5 |
| D | | GO TO STEP 9 |
|
.gif)
CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU)
(a) Disconnect the power management control ECU connector. Text in Illustration
|
 |
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
|---|---|---|
D43-12 (CA3P) - D43-11 (CA3N) |
Ignition switch off |
108 to 132 Ω |
| OK | | REPLACE POWER MANAGEMENT CONTROL ECU |
|
CHECK FOR OPEN IN CAN BUS WIRE (ECM)
(a) Reconnect the power management control ECU connector.
(b) Disconnect the ECM connector. Text in Illustration
|
 |
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
|---|---|---|
A49-12 (CANP) - A49-4 (CANN)*1 |
Ignition switch off |
108 to 132 Ω |
A41-8 (CANP) - A41-9 (CANN)*2 |
Ignition switch off |
108 to 132 Ω |
*1: for 1AR-FE
*2: for 2GR-FE
Result | Proceed to |
|---|---|
OK (for 1AR-FE) |
A |
OK (for 2GR-FE) |
B |
NG |
C |
| A | | REPLACE ECM |
| B | | REPLACE ECM |
|
CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 1 J/C MAIN WIRE)
(a) Reconnect the ECM connector.
(b) Disconnect the CAN No. 1 junction connector (D56).
(c) Disconnect the CAN No. 1 junction connector (A44). Text in Illustration
|
 |
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
|---|---|---|
D56-4 (CANH) - D56-15 (CANL) |
Ignition switch off |
108 to 132 Ω |
D56-3 (CANH) - D56-14 (CANL) |
Ignition switch off |
200 Ω or higher |
A44-8 (CANH) - A44-19 (CANL) |
Ignition switch off |
108 to 132 Ω |
Result | Proceed to |
|---|---|
OK |
A |
NG (to ECM main wire) |
B |
NG (to Power management ECU main wire) |
C |
| A | | REPLACE CAN NO. 1 J/C |
| B | | REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - ECM) |
| C | | REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU) |
CHECK FOR SHORT IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU)
(a) Disconnect the power management control ECU connector. Text in Illustration
|
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
|---|---|---|
D43-12 (CA3P) - D43-11 (CA3N) |
Ignition switch off |
108 to 132 Ω |
| OK | | REPLACE POWER MANAGEMENT CONTROL ECU |
|
CHECK FOR SHORT IN CAN BUS WIRES (ECM)
(a) Reconnect the power management control ECU connector.
(b) Disconnect the ECM connector. Text in Illustration
|
|
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
|---|---|---|
A49-12 (CANP) - A49-4 (CANN)*1 |
Ignition switch off |
108 to 132 Ω |
A41-8 (CANP) - A41-9 (CANN)*2 |
Ignition switch off |
108 to 132 Ω |
*1: for 1AR-FE
*2: for 2GR-FE
Result | Proceed to |
|---|---|
OK (for 1AR-FE) |
A |
OK (for 2GR-FE) |
B |
NG |
C |
| A | | REPLACE ECM |
| B | | REPLACE ECM |
|
CHECK FOR SHORT IN CAN BUS MAIN WIRE (CAN NO. 1 J/C MAIN WIRE)
(a) Reconnect the ECM connector.
(b) Disconnect the CAN No. 1 junction connector (D56).
(c) Disconnect the CAN No. 1 junction connector (A44). Text in Illustration
|
|
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
|---|---|---|
D56-4 (CANH) - D56-15 (CANL) |
Ignition switch off |
108 to 132 Ω |
D56-3 (CANH) - D56-14 (CANL) |
Ignition switch off |
200 Ω or higher |
A44-8 (CANH) - A44-19 (CANL) |
Ignition switch off |
108 to 132 Ω |
Result | Proceed to |
|---|---|
OK |
A |
NG (to ECM main wire) |
B |
NG (to Power management ECU main wire) |
C |
NG (to Air conditioning amplifier branch wire) |
D |
| A | | REPLACE CAN NO. 1 J/C |
| B | | REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - ECM) |
| C | | REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU) |
|
CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER)
(a) Disconnect the air conditioning amplifier connector.
(b) Measure the resistance according to the value(s) in the table below. Standard Resistance:
|
 |
| OK | | REPLACE AIR CONDITIONING AMPLIFIER |
| NG | | REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER) |
CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU)
(a) Disconnect the power management control ECU connector. Text in Illustration
|
 |
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
D43-12 (CA3P) - D43-6 (GND) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
D43-11 (CA3N) - D43-6 (GND) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
D43-12 (CA3P) - D43-1 (AM22) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
D43-11 (CA3N) - 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 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.
| OK | | REPLACE POWER MANAGEMENT CONTROL ECU |
|
CHECK FOR SHORT IN CAN BUS WIRES (ECM)
(a) for 1AR-FE
(1) Disconnect the ECM connectors.
Text in Illustration *1 |
Front view of wire harness connector (to ECM) |
(2) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
A49-12 (CANP) - B58-104 (E1) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
A49-4 (CANN) - B58-104 (E1) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
A49-12 (CANP) - A49-20 (BATT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
A49-4 (CANN) - A49-20 (BATT) |
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 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.
(b) for 2GR-FE
(1) Disconnect the ECM connectors.
Text in Illustration *1 |
Front view of wire harness connector (to ECM) |
(2) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose |
|---|---|---|---|
A41-8 (CANP) - B39-81 (E1) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
A41-9 (CANN) - B39-81 (E1) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
A41-8 (CANP) - A41-1 (BATT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
A41-9 (CANN) - A41-1 (BATT) |
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 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.
Result | Proceed to |
|---|---|
OK (for 1AR-FE) |
A |
OK (for 2GR-FE) |
B |
NG |
C |
| A | | REPLACE ECM |
| B | | REPLACE ECM |
|
CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C MAIN WIRE)
(a) Disconnect the CAN No. 1 junction connector (D56).
(b) Disconnect the CAN No. 1 junction connector (A44). Text in Illustration
|
 |
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition | Purpose | Connected to |
|---|---|---|---|---|
D56-4 (CANH) - D1-4 (CG) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
Power management control ECU |
D56-15 (CANL) - D1-4 (CG) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
|
D56-4 (CANH) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
|
D56-15 (CANL) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANL +B short |
|
D56-3 (CANH) - D1-4 (CG) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
Air conditioning amplifier |
D56-14 (CANL) - D1-4 (CG) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
|
D56-3 (CANH) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
|
D56-14 (CANL) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANL +B short |
|
A44-8 (CANH) - D1-4 (CG) |
Ignition switch off |
200 Ω or higher |
Inspection for CANH ground short |
ECM |
A44-19 (CANL) - D1-4 (CG) |
Ignition switch off |
200 Ω or higher |
Inspection for CANL ground short |
|
A44-8 (CANH) - D1-16 (BAT) |
Cable disconnected from negative (-) battery terminal |
6 kΩ or higher |
Inspection for CANH +B short |
|
A44-19 (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 Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.
Result | Proceed to |
|---|---|
OK |
A |
NG (to ECM main wire) |
B |
NG (to Power management control ECU main wire) |
C |
NG (to Air conditioning amplifier branch wire) |
D |
| A | | REPLACE CAN NO. 1 J/C |
| B | | REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - ECM) |
| C | | REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU) |
|
CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER)
(a) Disconnect the air conditioning amplifier connector.
(b) Measure the resistance according to the value(s) in the table below. Text in Illustration
Standard Resistance:
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 Bus Wire inspection. Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection. |
 |
| OK | | REPLACE AIR CONDITIONING AMPLIFIER |
| NG | | REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER) |
Test yourself
A quick Toyota Venza quiz: every answer comes with an explanation and a link to the manual page.