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 VSS connector.
Measure voltage of VSS battery power circuit between VSS harness connector and chassis ground.
Probe(+) : VSS harness connector NO3.
Probe(-) : Chassis ground.
Specification: Approximately 12V
Is the voltage within specification?
YES
Go to "Inspection of sensor signal line open"
NO
Open circuit or short circuit to chassis ground between VSS harness connector and battery power circuit
Repair as necessary and go to "Verification of Vehicle Repair" procedure
In case,when the connector of VSS is disconnected, the voltage of terminal 3 is 1V.
Possible cause:Open circuit or short circuit after I/P-J/BOX fuse(10A)
The voltage check of VSS ,after disconnection of VSS,is to check the pull-up voltage out of ECM and to check open or short.
Turn ignition switch to OFF and disconnect VSS connector and instrument cluster.
Measure voltege of VSS signal circuit between VSS harnece connector and ECM harness connector.
Probe(+) : VSS harness connector NO2.
Probe(-) : Chassis ground.
Specification: Approximately 5V
Is each voltege within specification?
YES
Go to "Inspection of open ground"
NO
Open or short circuit between VSS harnece connector and ECM harness connector
Bad ECM
Repair as necessary and go to "Verification of Vehicle Repair" procedure
1.In case,when the connector of VSS is disconnected, the voltage of terminal 2 is 0V.
▶Possible cause: If the terminal 2 voltage of VSS is 0V, the possible cause is likely to be open or bad ECM.
2.The voltage of terminal 2 is about 6.5~7.5V when the VSS connector is disconnected.
The purpose of checking terminal 2 after disconnecting VSS connector is to check open or short circuit of ground.
Turn ignition switch to OFF and disconnect VSS connector.
Measure resistance or voltage of VSS ground circuit between VSS harnece connector and chassis ground.
Probe(+) : VSS harness connector NO1.
Probe(-) : Chassis ground.
Specification: below 1Ω, below 0.5V
Is the resistance or voltage within Specification?
YES
Go to "Inspection of signal circuit short"
NO
Open circuit between VSS harnece connector and Chassis ground
Repair as necessary and go to "Verification of Vehicle Repair" procedure
When the voltage of VSS terminal 2 is 0V, the inspection of short circuit is recommended to find open or short circuit of signal line.
Turn ignition switch to OFF and disconnect VSS connector and ECM connector and instrument cluster.
Measure resistance of VSS signal circuit between VSS ground circuit and ECM harnece connector and Chassis ground.
Probe(+) : VSS signal circuit harness connector NO2.
Probe(-) : VSS ground circuit harness connector NO1.
Specification: infinite
Does the resistance indicate open circuit?
YES
Go to "Inspecion of ECM"
NO
Short circuit to chassis ground between VSS harness connector and ECM harness connector
short circuit between VSS signal circuit and ground circuit
Repair as necessary and go to "Verification of Vehicle Repair" procedure
