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
Go to "Power Circuit Inspection" procedure.
IG KEY : OFF , Engine : OFF
Disconnect MAFS connector(C55).
IG KEY : ON , Engine : OFF
Measure voltage between terminal 4 of the MAFS harness connector C55 and chassis ground.
Specification(a) : Approx. B+
Measure voltage between terminal 2 of the MAFS harness connector C55 and chassis ground.
Specification(b) : Approx. 5V
Is the voltage near the specified value?
YES
Go to step "Signal Circuit Inspection" procedure.
NO
Especially check blown or open 15A injector fuse
Check for open in the power supply circuit between the MAF sensor and main relay.
Repair as necessary and go to "Verification of Vehicle Repair" procedure
IG KEY : OFF , Engine : OFF
Disconnect MAFS connector(C55) and ECM connector C21-2.
Measure resistance between terminal 1 of the MAFS harness connectorC55 and 15 of the ECM harness connectorC21-2
Specification : Approx. 0Ω
Is resistance display near the specified value?
YES
Go to "Check for Short to Ground in Harness" procedure.
NO
Repair as necessary and go to "Verification of Vehicle Repair" procedure
IG KEY : OFF , Engine : OFF
Disconnect MAFS connector(C55).
Measure resistance between terminal 1 of the MAFS harness connectorC55 and chassis ground.
Specification : Approx. ∞
Is the resistance near the specified value?
YES
Go to "Component Inspection" procedure
NO
Repair as necerssary and go to "Verification of Vehicle Repair" procedure
