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
Turn ignition switch to OFF and disconnect ISCA connector.
With ignition switch to ON
Measure voltage of ISCA battery power circuit between ISCA harness connector and chassis ground.
Probe(+) : ISCA harness connector NO2.
Probe(-) : Chassis ground.
Specification: Approximately 12V
Is the voltege within specification?
YES
Go to "OPEN CIRCUIT INSPECTON FOR SIGNAL"
NO
Short circuit to chassis ground between ISCA harness connector and control relay
Open circuit between ISCA harness connector and control re
Repair as necessary and go to "Verification of Vehicle Repair"
1.In case,when ISCA connector is disconnected, the voltage of ISCA terminal 2 is 0V.
▶Possible cause: Open or short circuit in battery power line after fuse (15A INJ).
2.ECM also sets P1505 and P1507 if it detects the open circuit in ISCA power line.
Turn ignition switch to ON.
Measure voltage of ISCA battery power circuit between ECM harness connector and chassis ground.
Probe(+) : ECM harness connector NO26 and NO29.
Probe(-) : Chassis ground.
Specification: Approximately 3.6V
Is each voltage within specification?
YES
Go to "Short circuit inspection for ISCA opening or closing"
NO
Open circuit between ISCA harness connector and ECM harness connector
Repair as necessary and go to "Verification of Vehicle Repair"
Turn ignition switch to OFF and disconnect ISCA harness connector and ECM harness connector.
Measure resistance between ISCA harness connector and Chassis ground at ISCA signal circuit.
Probe(+) : ISCA harness connector NO1 and NO3.
Probe(-) : Chassis ground.
Specification: infinite
Does each resistance indicate continuity circuit?
YES
Go to "Short Circuit Inspection for ISCA Opening or Closing"
NO
Short circuit between ISCA open signal circuit and close signal circuit
Repair as necessary and go to "Verification of Vehicle Repair"
Turn ignition switch to OFF and disconnect ISCA harness connector and ECM harness connector.
Check resistance between ISCA open signal circuit and close signal circuit.
Probe(+) : ISCA harness connector NO1.
Probe(-) : ISCA harness connector NO3.
Specification: nfinite
Does each resistance indicate continuity circuit?
YES
Go to "Component Inspection"
NO
Short circuit between ISCA open signal circuit and close signal circuit
Repair as necessary and go to "Verification of Vehicle Repair"
