3782178

1.

Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

3.

Has a problem been found?

YES

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure

NO

▶ Go to " Power Circuit Inspection " procedure.

1.

Check voltage

(1)

IG "OFF".

(2)

Disconnect the PCM connector.

(3)

IG "ON" and ENG "OFF"

(4)

During taking off the brake : Measure the voltage between terminal 23 of PCM harness connector and chassis ground.

(5)

During stepping on the brake : Measure the voltage between terminal 23 of PCM harness connector and chassis ground.

a.

Specification :

Item	During taking off the brake	During stepping on the brake
Brake Lamp Switch	0V	Battery voltage
Brake Switch	Battery voltage	0V

(6)

Is the measured voltage within specification ?

YES

▶ Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair as necessary and go to "Verification of Vehicle Repair" procedure.

NO

▶ Go to "Check open in harness" as follows.

2.

Check open in harness

(1)

IG "OFF".

(2)

Disconnect the brake switch and PCM connector.

(3)

Measure the resistance between terminal 23 of PCM harness connector and terminal 1 of Brake switch harness connector.

a.

Specification : Approx. below 1Ω

(4)

Is the measured resistance within specification ?

YES

▶ Go to "Check voltage" as follows.

NO

▶ Repair open in circuit and go to "Verification of Vehicle Repair" procedure.

3.

Check voltage

(1)

IG "OFF".

(2)

Disconnect the brake switch connector.

(3)

Measure the voltage between brake lamp switch terminal 2 and chassis ground.

(4)

Measure the voltage between brake switch terminal 4 and chassis ground.

(5)

IG Key "ON".

(6)

Measure the voltage between brake lamp switch terminal 2 and chassis ground.

(7)

Measure the voltage between brake switch terminal 4 and chassis ground.

a.

Specification :

Item	IG "OFF"	IG "ON"
Brake Lamp Switch	Battery voltage	Battery voltage
Brake Switch	0V	Battery voltage

(8)

Is the measured voltage within specification ?

YES

▶ Substitute with a known - good brake switch and check for proper operation. If the problem is corrected, replace brake switch and go to "Verification of Vehicle Repair" procedure..

NO

▶ Check the fuse between battery and brake switch.

▶ Repair open or short in power circuit of brake switch and go to "Verification of Vehicle Repair" procedure.