DRL troubleshooting: DRL do not operate (turn signals normal)

T-79prose procedure

Canada-spec DRL troubleshooting.

IMPORTANT

Symptom: Daytime running lights (DRL) do not operate. (Turn signals function normally.)

NOTE

DRL operate with engine runing and following switches are off: • Headlight switch • Turn signal switch • Hazard warning switch • Parking brake switch (Parking brake released)

Step 1

1
Turn on the ignition switch.
Position the vehicle on a flat surface and block the wheels to prevent vehicle movement.
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2
Measure the voltage at the following terminal-wires of the DRL unit.
3
If correct, replace the DRL unit.

Step 1 DRL unit terminal voltage check

Wire	Connected to	Test condition	Specification	Action
(L)	WIPER 20A fuse	Constant	12V	Repair wire (L) (WIPER 20A—DRL unit)
(B)	Ground	Constant	0V	Repair wire (B) (DRL unit—Body ground)
(R)	Parking brake switch	Parking brake released	12V	Go to Step 2
(W/R)	Headlight switch	Headlight switch off	0V	Go to Step 3

(L)

Connected toWIPER 20A fuse

Test conditionConstant

Specification12V

ActionRepair wire (L) (WIPER 20A—DRL unit)

(B)

Connected toGround

Test conditionConstant

Specification0V

ActionRepair wire (B) (DRL unit—Body ground)

(R)

Connected toParking brake switch

Test conditionParking brake released

Specification12V

ActionGo to Step 2

(W/R)

Connected toHeadlight switch

Test conditionHeadlight switch off

Specification0V

ActionGo to Step 3

Step 2

1
Disconnect the parking brake switch connector.
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2
Check continuity between the terminal of the switch and a body ground.
3
If not as specified, adjust or replace the parking brake switch.
4
If correct, repair wires (R) and (L/Y). (Parking brake switch — DRL unit)

Step 2 Parking brake switch continuity

Parking brake lever	Continuity
Pulled one notch	Yes
Released	No

Pulled one notch

ContinuityYes

Released

ContinuityNo

Step 3

1
Remove the column cover and disconnect the connectors of the headlight switch.
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2
Check continuity between the terminals of the headlight switch connector.
3
If not as specified, replace the headlight switch.
4
If correct, repair wire (W/R). (Headlight switch — DRL unit)

Step 3 Headlight switch continuity

Position	Terminal BTN	Terminal TNS
Headlight switch ON	O	O
Headlight switch OFF

Headlight switch ON

Terminal BTNO

Terminal TNSO

Headlight switch OFF

Terminal BTN

Terminal TNS

O—O: Indicates continuity

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