CAN COMMUNICATION SYSTEM, Diagnostic DTC:U0164
| DTC Code | DTC Name |
|---|---|
| U0164 | Lost Communication with HVAC Control Module |
DESCRIPTION
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| U0164 | No communication from the air conditioning amplifier assembly continues. |
|
Tech Tips
The diagnosis procedure is for when DTC U0164 is output by the power management control ECU (GTS display: PM1 Gateway).
WIRING DIAGRAM
INSPECTION PROCEDURE
Note
-
Turn the power switch off before measuring the resistances between CAN main bus wires and between CAN main bus branch wires.
-
Turn the power switch off before inspecting CAN bus wires for a ground short.
-
After the power 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 power 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.
Tech Tips
-
Operating the power 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.
PROCEDURE
-
RECONFIRM DTC OUTPUT
-
Reconfirm DTCs.
Tech Tips
If power management bus DTC U1002 is output from the power management control ECU (GTS display: PM1 Gateway), troubleshoot for U1002 and check for malfunctions in the V2 main bus circuit.
Result Result Proceed to U1002 is not output from power management control ECU (GTS display: PM1 Gateway) A U1002 is output from power management control ECU (GTS display: PM1 Gateway) B
B 
GO TO CIRCUITS INDICATED BY OUTPUT DTCS Click here
A 
-
-
CHECK FOR OPEN IN CAN BUS WIRES (AIR CONDITIONING AMPLIFIER ASSEMBLY BRANCH WIRE)
-
Disconnect the cable from the negative (-) auxiliary battery terminal.
-
Text in Illustration *a Front view of wire harness connector
(to Air Conditioning Amplifier Assembly)
Disconnect the L14 air conditioning amplifier assembly connector.
-
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition L14-11 (CANH) - L14-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
NG
REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY BRANCH WIRE)
OK
-
-
CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)
-
Text in Illustration *a Front view of wire harness connector
(to Air Conditioning Amplifier Assembly)
Measure the resistance according to the value(s) in the table below.
Standard Resistance Tester Connection Condition Specified Condition L14-14 (GND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)
OK
-
-
CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)
-
Connect the cable to the negative (-) auxiliary battery terminal.
-
Text in Illustration *a Front view of wire harness connector
(to Air Conditioning Amplifier Assembly)
Measure the voltage according to the value(s) in the table below.
Standard Voltage Tester Connection Condition Specified Condition L14-1 (IG+) - Body ground Power switch on (IG) 11 to 14 V
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK 
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here
-