DTC Troubleshooting: B1038
DTC B1038: IMMOBILIZER F-CAN Authentication ID Not Received
NOTE:
Before you troubleshoot, review the general troubleshooting information.
According to the detected DTC(s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the body control module.
Refer to the DTC shown on the display, then inspect the connectors and terminals based on the instructions.

DTC Description
DTC
B1038 IMMOBILIZER F-CAN Authentication ID Not Received
  

1.
CAN gateway system DTC check:

CAN gateway system DTC check
?1.
Turn the vehicle to the ON mode.

?2.
Check for CAN gateway system DTCs with the HDS.
DTC Description
DTC
U0029-00 CAN Gateway F-CAN ch A Bus Off
  
U0047-00 CAN Gateway F-CAN ch B Bus Off
  
U3000-49 CAN Gateway Internal Failure
  


Is DTC U0029-00, U0047-00, and/or U3000-49 indicated?

     
YES
     
     
     
     
NO
     
     
     
Go to step 2.
2.
F-CAN circuit communication check:

F-CAN circuit communication check
?1.
Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

  

Does the body control module detect the CAN gateway Bus channels A?

     
Bus A is Not Available
     
     
     
Go to step 3.
     
Bus A is Available
     
     
     
Go to step 4.
3.
Open wire check (F-CAN A lines):

Open wire check (F-CAN A lines)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
CAN gateway 12P connector*1
CAN gateway 16P connector*2
Body control module connector B (36P)
*1: CAN gateway 12P connector type
*2: CAN gateway 16P connector type

?3.
Check for continuity between test points 1 and 2 respectively.
CAN gateway 12P connector type
Test condition
Vehicle OFF (LOCK) mode
CAN gateway 12P connector: disconnected
Body control module connector B (36P): disconnected
Test point 1
CAN gateway 12P connector No. 3
Test point 2
Body control module connector B (36P) No. 22

Test point 1
CAN gateway 12P connector No. 9
Test point 2
Body control module connector B (36P) No. 23

CAN gateway 16P connector type
Test condition
Vehicle OFF (LOCK) mode
CAN gateway 16P connector: disconnected
Body control module connector B (36P): disconnected
Test point 1
CAN gateway 16P connector No. 3
Test point 2
Body control module connector B (36P) No. 22

Test point 1
CAN gateway 16P connector No. 11
Test point 2
Body control module connector B (36P) No. 23


Is there 1.0 ? or less?

     
YES
     
     
     
The F-CAN A_H and F-CAN A_L wires are OK. Check for poor connections or loose terminals at the CAN gateway and the body control module. Substitute a known-good body control module, then recheck. If the DTC B1038 goes away and the body control module was substituted, replace the original body control module.?
     
NO
     
     
     
Repair an open in F-CAN A_H or F-CAN A_L wire between the CAN gateway and the body control module.?
4.
F-CAN circuit communication check (Transmitting control unit):

F-CAN circuit communication check (Transmitting control unit)
?1.
Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

  

?2.
According to the detected DTC on the following table, make sure that the transmitting control unit detects the CAN gateway Bus channels normally.
DTC
Transmitting control unit
Detected CAN gateway Bus channels at normal
B1038
VSA modulator-control unit
A, B

Is it detected normally?

     
Detected normal
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the transmitting control unit and the CAN gateway.?
     
U0122: VSA modulator-control unit is Not Available for Bus A
     
     
     
Go to step 5.
     
U0122: VSA modulator-control unit is Not Available for Bus B
     
     
     
Go to step 6.
5.
Open wire check (F-CAN A lines):

Open wire check (F-CAN A lines)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
According to the detected DTC on the following table, disconnect the transmitting control unit connectors.
DTC
Connector
-
CAN gateway 12P connector*1
CAN gateway 16P connector*2
B1038
VSA modulator-control unit 46P connector
*1: CAN gateway 12P connector type
*2: CAN gateway 16P connector type

?3.
Check for continuity between test points 1 and 2.
CAN gateway 12P connector type
Test condition
Vehicle OFF (LOCK) mode
CAN gateway 12P connector: disconnected
Transmitting control unit connector for indicated DTCs: disconnected

DTC
Circuit name
Test point 1 (Receiving control unit)
Test point 2 (Transmitting control unit)
Connector
Terminal
Connector
Terminal
B1038
F-CAN A_H
CAN gateway 12P connector
No. 3
VSA modulator-control unit 46P connector
No. 20
F-CAN A_L
No. 9
No. 21

CAN gateway 16P connector type
Test condition
Vehicle OFF (LOCK) mode
CAN gateway 16P connector: disconnected
Transmitting control unit connector for indicated DTCs: disconnected

DTC
Circuit name
Test point 1 (Receiving control unit)
Test point 2 (Transmitting control unit)
Connector
Terminal
Connector
Terminal
B1038
F-CAN A_H
CAN gateway 16P connector
No. 3
VSA modulator-control unit 46P connector
No. 20
F-CAN A_L
No. 11
No. 21


Is there 1.0 ? or less?

     
YES
     
     
     
The F-CAN A_H wire and the F-CAN A_L wire are OK.
Refer to the DTC shown on the display, replace the control unit based on the instructions (see table).?
DTC
Operation for transmitting control unit
B1038
Replace the VSA modulator-control unit.
     
NO
     
     
     
Repair an open in F-CAN A_H or F-CAN A_L wire between the CAN gateway and the transmitting control unit.?
6.
Open wire check (F-CAN B lines):

Open wire check (F-CAN B lines)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
According to the detected DTC on the following table, disconnect the transmitting control unit connectors.
DTC
Connector
-
CAN gateway 12P connector*1
CAN gateway 16P connector*2
B1038
VSA modulator-control unit 46P connector
*1: CAN gateway 12P connector type
*2: CAN gateway 16P connector type

?3.
Check for continuity between test points 1 and 2.
CAN gateway 12P connector type
Test condition
Vehicle OFF (LOCK) mode
CAN gateway 12P connector: disconnected
Transmitting control unit connector for indicated DTCs: disconnected

DTC
Circuit name
Test point 1 (Receiving control unit)
Test point 2 (Transmitting control unit)
Connector
Terminal
Connector
Terminal
B1038
F-CAN B_H
CAN gateway 12P connector
No. 12
VSA modulator-control unit 46P connector
No. 24
F-CAN B_L
No. 5
No. 25

CAN gateway 16P connector type
Test condition
Vehicle OFF (LOCK) mode
CAN gateway 16P connector: disconnected
Transmitting control unit connector for indicated DTCs: disconnected

DTC
Circuit name
Test point 1 (Receiving control unit)
Test point 2 (Transmitting control unit)
Connector
Terminal
Connector
Terminal
B1038
F-CAN B_H
CAN gateway 16P connector
No. 6
VSA modulator-control unit 46P connector
No. 24
F-CAN B_L
No. 14
No. 25


Is there 1.0 ? or less?

     
YES
     
     
     
The F-CAN B_H wire and the F-CAN B_L wire are OK.
Refer to the DTC shown on the display, replace the control unit based on the instructions (see table).?
DTC
Operation for transmitting control unit
B1038
Replace the VSA modulator-control unit.
     
NO
     
     
     
Repair an open in F-CAN B_H or F-CAN B_L wire between the CAN gateway and the transmitting control unit.?