Many malfunctions in the electrical system are caused by poor harness(s) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Check the following conditions:
Check for damaged harness and terminals: contact resistance, oxidation, bent or broken terminals.
Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection
Use a suitable male pin to ensure that contact in sockets is good. The pin should remain in position when pulled gently.
Has a problem been found?
YES
Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
System OK.Go to "Verification of Vehicle Repair" procedure
When ECM detects open circuit of ECTS,it assumes ECTS data as 5V and - 39℃.
Turn ignition switch to OFF and disconnect ECTS connector.
Turn ignition switch to ON
Measure voltage of ECTS signal circuit..
Probe(+) : ECTS harness connector NO4.
Probe(-) : Chassis ground.
Specification: Approximately 5V
Is volage within Specification?
YES
Go to "Output Voltage Inspection for ECTS"
NO
In case over 5V : Short circuit to battery between ECTS harness connector and ECM harness connector
In case 0V: Open circuit between ECTS harness connector and ECM harness connector
Repair as necessary and go to "Verification of Vehicle Repair" procedure
1.In case,when ECTS connector is disconnected,the voltage at terminal 4 is 0V.
▶Possible cause : Open or short between Terminal 4 of ETCS connector and terminal 39 of ECM.
When ECM detects open circuit of ECTS,it assumes ECTS data as 5V and - 39℃.
Turn ignition switch to OFF and disconnect ECTS harness connector.
Measure resistance or voltage of ETCS ground circuit between ETCS harness connector and chassis ground.
Probe(+) : ETCS harness connector NO3.
Probe(-) : chassis ground.
Specification: below 1Ω,below 0.5V
Does each resistance or voltage indicate continuity circuit?
YES
Go to "Component Inspection"
NO
Open circuit between ECTS harness connector and ECM harness connector
Open circuit between ECM harness connector and chassis ground
Repair as necessary and go to "Verification of Vehicle Repair" procedure
In case,when checking the open circuit for ground,resistence is infinite.
▶Possible cause : Open circuit in ground line, Check open circuit for ECM ground, Check open circuit between ECM terminal 35 and ECTS terminal 35.
