DTC Troubleshooting: C1270-15
DTC C1270-15: Automatic Brake Hold Switch Signal Circuit Open
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
DTC
Freeze Frame
C1270-15 Automatic Brake Hold Switch Signal Circuit Open
    

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Turn the vehicle to the OFF (LOCK) mode, then to the ON mode.

?4.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
C1270-15 Automatic Brake Hold Switch Signal Circuit Open
    

Is DTC C1270-15 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the Freeze data/on-board snapshot.?
2.
Open wire check (BRAKE HOLD line) 1:

Open wire check (BRAKE HOLD line) 1
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Automatic brake hold switch 4P connector

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Automatic brake hold switch 4P connector: disconnected
Test point 1
Automatic brake hold switch 4P connector No. 2
Test point 2
Body ground


Is there about 5 V?

     
YES
     
     
     
The BRAKE HOLD wire is OK. Go to step 3.
     
NO
     
     
     
If about 12 V is indicated. Go to step 5.
     
NO
     
     
     
If about 0 V is indicated. Go to step 7.
3.
Open wire check (GND line):

Open wire check (GND line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Automatic brake hold switch 4P connector: disconnected
Test point 1
Automatic brake hold switch 4P connector No. 1
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Repair an open in the wire between the automatic brake hold switch and body ground (G503).?
4.
Automatic brake hold switch check:

Automatic brake hold switch check
?1.
Check the automatic brake hold switch.

Is the automatic brake hold switch OK?

     
YES
     
     
     
Check for loose terminals and poor connections in the VSA modulator-control unit 46P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the VSA modulator-control unit.?
     
NO
     
     
     
5.
Shorted wire check (BRAKE HOLD line to power):

Shorted wire check (BRAKE HOLD line to power)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Gauge control module connector A (32P)

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Automatic brake hold switch 4P connector: disconnected
 
Gauge control module connector A (32P): disconnected
Test point 1
Automatic brake hold switch 4P connector No. 2
Test point 2
Body ground


Is there 0.1 V or more?

     
YES
     
     
     
Repair a short to power in the wire between the automatic brake hold switch and the gauge control module.?
     
NO
     
     
     
Go to step 6.
6.
Gauge control module check (substitution):

Gauge control module check (substitution)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Substitute a known-good gauge control module.

?3.
Reconnect the following connectors.
Automatic brake hold switch 4P connector
Gauge control module connector A (32P)

?4.
Turn the vehicle to the ON mode.

?5.
Clear the DTC with the HDS.


?6.
Turn the vehicle to the OFF (LOCK) mode, then to the ON mode.

?7.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
C1270-15 Automatic Brake Hold Switch Signal Circuit Open
    

Is DTC C1270-15 indicated?

     
YES
     
     
     
Check for loose terminals and poor connections in the VSA modulator-control unit 46P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the VSA modulator-control unit.?
     
NO
     
     
     
7.
Open wire check (BRAKE HOLD line) 2:

Open wire check (BRAKE HOLD line) 2
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Gauge control module connector A (32P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Automatic brake hold switch 4P connector: disconnected
 
Gauge control module connector A (32P): disconnected
Test point 1
Automatic brake hold switch 4P connector No. 2
Test point 2
Gauge control module connector A (32P) No. 12


Is there continuity?

     
YES
     
     
     
Go to step 8.
     
NO
     
     
     
Repair an open in the wire between the automatic brake hold switch and the gauge control module.?
8.
Gauge control module check (substitution):

Gauge control module check (substitution)
?1.
Substitute a known-good gauge control module.

?2.
Reconnect the following connectors.
Automatic brake hold switch 4P connector
Gauge control module connector A (32P)

?3.
Turn the vehicle to the ON mode.

?4.
Clear the DTC with the HDS.


?5.
Turn the vehicle to the OFF (LOCK) mode, then to the ON mode.

?6.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
C1270-15 Automatic Brake Hold Switch Signal Circuit Open
    

Is DTC C1270-15 indicated?

     
YES
     
     
     
Check for loose terminals and poor connections in the VSA modulator-control unit 46P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the VSA modulator-control unit.?
     
NO