DTC Troubleshooting: C1040-00 (VSA Control Unit)

DTC Troubleshooting: C1040-00

DTC C1040-00: Different Diameter Tire is Detected

NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description	DTC	Freeze Frame
C1040-00 Different Diameter Tire is Detected

Tire check:

Tire check

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Check all four tires for size, inflation, and wear.

Are all four tires the correct size, properly inflated, and worn evenly?


	YES

Go to step 2.


	NO

Swap the wheels and tires with a known-good set (the correct size, type, and properly inflated), then test-drive the vehicle again.?

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 start the engine.

?4.	Test-drive the vehicle at 12 mph (20 km/h) or more for 72 seconds or more. NOTE: Drive the vehicle on the road, not on a lift.

?5.

Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame
C1040-00 Different Diameter Tire is Detected

Is DTC C1040-00 indicated?


	YES

The failure is duplicated. Go to step 3.


	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.?

Wheel speed sensor performance check:

Wheel speed sensor performance check

?1.	Test-drive the vehicle at 12 mph (20 km/h) or more in a straight line. NOTE: Drive the vehicle on the road, not on a lift.

?2.

Check the parameter(s) below with the HDS.

Signal	Current conditions
Signal	Values	Unit
RIGHT FRONT WHEEL SPEED
LEFT FRONT WHEEL SPEED
RIGHT REAR WHEEL SPEED
LEFT REAR WHEEL SPEED

Is any one of the four values different?


	YES

Go to step 4.


	NO

Go to step 6.

Wheel speed sensor check (substitution):

Wheel speed sensor check (substitution)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Substitute a known-good wheel speed sensor.

?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 start the engine.

?6.	Test-drive the vehicle at 12 mph (20 km/h) or more for 72 seconds or more. NOTE: Drive the vehicle on the road, not on a lift.

?7.

Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame
C1040-00 Different Diameter Tire is Detected

Is DTC C1040-00 indicated?


	YES

Go to step 5.


	NO

Replace the original wheel speed sensor.?

Magnetic encoder check:

Magnetic encoder check

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.

Inspect the magnetic encoder for damage, debris, and correct installation.

	Front: Remove the driveshaft outboard joint from the appropriate wheel hub.
	Rear: Remove the hub bearing unit.

Is the magnetic encoder surface OK?


	YES

Go to step 6.


	NO

Clean the debris from the appropriate magnetic encoder surface on the wheel bearing or the hub bearing unit. If the debris cannot be removed or the encoder is damaged, replace the appropriate wheel bearing or the hub bearing unit. Then recheck for DTCs. If the DTC is still present go to step 6.

VSA modulator-control unit check (update):

VSA modulator-control unit check (update)

?1.	Update the VSA modulator-control unit if it does not have the latest software.

?2.	Turn the vehicle to the OFF (LOCK) mode, then start the engine.

?3.	Test-drive the vehicle at 12 mph (20 km/h) or more for 72 seconds or more. NOTE: Drive the vehicle on the road, not on a lift.

?4.

Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame

Is DTC C1040-00 indicated?


	YES

Check for loose terminals and poor connections in the VSA modulator-control unit 38P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit.?


	NO

Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.?