DTC Troubleshooting: C1C21-14

DTC C1C21-14: Back-Up Light Switch Stuck OFF

NOTE:

	Before you troubleshoot, review the general troubleshooting information.
	If DTC U0029-00 is indicated at the same time, do the DTC U0029-00 troubleshooting first.

DTC Description	DTC	Freeze Frame
C1C21-14 Back-Up Light Switch Stuck OFF

Back-up lights check:

Back-up lights check

?1.	Turn the vehicle to the ON mode.

?2.	Check the back-up lights when the shift lever is in reverse.

Are the back-up lights on?


	YES

Go to step 6.


	NO

Go to step 2.

Back-up light bulbs check:

Back-up light bulbs check

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

?2.	Check the back-up light bulbs.

Are the back-up light bulbs OK?


	YES

Go to step 3.


	NO

Replace the back-up light bulb, then retest.

Fuse check:

Fuse check

?1.

Check the following fuse.

Fuse	No. C34 (7.5 A)
Location	Under-dash fuse/relay box

Is the fuse OK?


	YES

The fuse is OK. Reinstall the fuse, then go to step 4.


	NO

Replace the fuse. Turn the vehicle to the ON mode, then to the OFF (LOCK) mode. If the fuse blows again, repair the short to ground on the No. C34 (7.5 A) fuse circuit.?

Back-up light switch check 1:

Back-up light switch check 1

?1.

Disconnect the following connector.

Back-up light switch 2P connector

?2.

On the switch side, check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Back-up light switch 2P connector: disconnected
Test point 1	Back-up light switch 2P connector No. 1
Test point 2	Back-up light switch 2P connector No. 2

Is there continuity when the shift lever is in reverse, and no continuity when the shift lever is in neutral?


	YES

Repair an open in the wire between the back-up light switch and the under-dash fuse/relay box.?


	NO

The back-up light switch wires are not open. Go to step 5.

Back-up light switch check 2:

Back-up light switch check 2

?1.	Check the back-up light switch.

Is the back-up light switch OK?


	YES

Check the reverse shift mechanism in the transmission.?


	NO

Replace the back-up light switch.?

Back-up light switch performance check:

Back-up light switch performance check

?1.

Check the parameter(s) below with the HDS.

Signal	Current conditions
Signal	Values	Unit
BACK-UP LIGHT SWITCH

Does it indicate ON when the shift lever is in reverse, and OFF when the shift lever is in neutral?


	YES

Go to step 9.


	NO

Go to step 7.

Body electrical system DTC check:

Body electrical system DTC check

?1.

Check for gauge control module DTCs with the HDS.

DTC Description	DTC

Are any DTCs indicated?


	YES

Go to indicated DTC's troubleshooting.?


	NO

Go to step 8.

Open wire check (BACK LT- line):

Open wire check (BACK LT- line)

?1.	Shift the shift lever into reverse.

?2.

Measure the voltage between test points 1 and 2 without disconnecting the under-dash fuse/relay box connector Q (40P).

Test condition	Vehicle ON mode
Test point 1	Under-dash fuse/relay box connector Q (40P) No. 29
Test point 2	Body ground

Is there battery voltage?


	YES

The BACK LT- wire is OK. Replace the MICU.?


	NO

Repair an open in the wire between the back-up light switch and the fuse box.?

VSA modulator-control unit check:

VSA modulator-control unit check

?1.	Clear the DTC with the HDS.

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

?3.	Shift the shift lever into reverse, then test-drive the vehicle backward for 2 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
C1C21-14 Back-Up Light Switch Stuck OFF

Is DTC C1C21-14 indicated?


	YES

Go to step 10.


	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.?

10.

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.

?3.	Shift the shift lever into reverse, then test-drive the vehicle backward for 2 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 C1C21-14 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.?