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
Checking the circuit of MAP power line is to find whether there is open or short circuit in MAP harness.
Turn ignition switch to OFF and disconnect MAP connector.
Turn ignition switch to ON
Measure voltage of TPS reference voltage(5V) circuit between MAP harness connector and ECM harness connector.
Probe(+) : MAP harness connector NO2.
Probe(-) : Chassis ground.
Specification: Approximately 5V
Is voltage within Specification?
YES
Go to "Inspection of short between MAP signal line and ground line
NO
Open circuit or short circuit to chassis ground between MAP harness connector and reference voltage
Open circuit or short circuit to chassis ground between MAP harness connector and ECM connector
Repair as necessary and go to "Verification of Vehicle Repair"
1.In case,when MAP connector is disconnected,the voltage of MAP terminal 2 is 0 V.
Possible cause: Open or short between terminal 33 of ECM and Terminal 2 of MAP
Checking open circuit of MAP signal line is to find whether there is open or short circuit in MAP harness.
Turn ignition switch to OFF and disconnect MAP sensor connector.
Turn ignition switch to ON
Measure voltage of MAP signal circuit between MAP harness connector and ECM harness connector.
Probe(+) : MAP harness connector NO1.
Probe(-) : Chassis ground.
Specification: Approximately 5V
Is voltage within Specification?
YES
Go to "Inspection of ECM "
NO
Open circuit or short circuit to chassis ground between TPS harness connector and signal circuit
Open circuit between TPS harness connector and ECM harness connector
Repair as necessary and go to "Verification of Vehicle Repair"
1.In case,when MAP connector is disconnected,the voltage of MAP terminal 1 is 0 V.
▶Possible cause: Open or short between terminal 16 of ECM and Terminal 1 of MAP.
