Testing If Display Is - 40 °C

-- Disconnect the MAP / IAT sensor -G71 / G42- electrical harness connector.

-- Using a jumper wire, connect the MAP / IAT sensor -G71 / G42- electrical harness connector terminals 1 to 2.

-- Turn the ignition switch ON

-- Check the value indicated on the scan tool display.

-- Switch ignition OFF.

If Indication Jumps To Approx. 140 °C: 

-- Replace the MAP / IAT sensor -G71 / G42-.

If indication remains at approx. -40 °C or -46 °C:

Checking Wiring 

-- Remove the Engine Control Module (ECM) -J623-.

-- Using a multimeter, check the MAP / IAT sensor -G71 / G42- electrical harness connector terminal 2 to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminal 42 for an open circuit or a short to voltage. Refer to Appropriate System Diagrams for pin locations.

-- Using a multimeter, check the MAP / IAT sensor -G71 / G42- electrical harness connector terminal 1 to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminal 13 for an open, high resistance or a short to voltage. Refer to Appropriate System Diagrams for pin locations.

Specified Resistance: 1.5 Ω Max. 

If The Specified Value Was Not Obtained: 

-- Check the wiring for an open, high resistance or short circuit to Battery (+).

-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

-- If necessary, repair the faulty wiring connection.

If No Malfunction Is Detected In The Wiring: 

-- Replace the Engine Control Module (ECM) -J623-.