Toyota Tundra Service Manual: Stop Light Control Relay

On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. CHECK STOP LIGHT CONTROL RELAY

(a) Remove the stop light control relays (BRK NO. 1) from the engine room relay block.

(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:

for BRK NO. 1

Tester Connection	Condition	Specified Condition
3 - 4	When battery voltage is not applied to terminals 1 and 2	10 kΩ or higher
3 - 5	When battery voltage is not applied to terminals 1 and 2	Below 1 Ω
3 - 4	When battery voltage is applied to terminals 1 and 2	10 kΩ or higher
3 - 5	When battery voltage is applied to terminals 1 and 2	Below 1 Ω

If the result is not as specified, replace the relay.

Toyota Tundra Service Manual > Trailer Brake Control System: Stop Light Control Relay Malfunction (C1380)
DESCRIPTION The skid control ECU (brake actuator assembly) sends a stop light operation request signal to the stop light control relay. If the skid control ECU (brake actuator assembly) detects a malfunction in the stop light control relay circuit, the trailer brake control ECU (brake control with b ...

Toyota Tundra Owners Manual