Exhaust Gas Temperature Sensor 1, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram.

Test requirements 

• The Engine Control Module (ECM) - J623- fuses OK.
• The Fuel Pump (FP) Relay -J17- must be OK.
• Battery voltage at least 12.5 volts.
• All electrical consumers such as, lights and rear window defroster, switched off.
• Vehicles with automatic transmission, shift selector lever into position "P" or "N".
• A/C switched off.
• Ground (GND) connections between engine/transmission/chassis OK.

Test procedure 

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK 

Start diagnosis 

Checking internal resistance

-- Disconnect the Exhaust Gas Temperature (EGT) Sensor 1 -G235- electrical harness connector.

-- Using a multimeter, check the Exhaust Gas Temperature (EGT) Sensor 1 -G235- terminals 1 to 2 for resistance.

Specified value: ∞ Ω (INFINITE)

If the specification was not obtained:

-- Replace the Exhaust Gas Temperature (EGT) Sensor 1 -G235-.

If the specification was obtained:

Checking Voltage supply 

-- Disconnect the Exhaust Gas Temperature (EGT) Sensor 1 -G235- electrical harness connector -1-.

-- Switch the ignition on.

-- Using a multimeter, check the Exhaust Gas Temperature (EGT) Sensor 1 -G235- electrical harness connector terminals 1 to 2 for voltage.

Specified value: 0.400 to 0.500 V.

-- Switch the ignition off.

If any of the specified values was not obtained:

Checking wiring 

If the manufacturers test box is being used, perform the following step.

-- Install the Test Box.

If the manufacturers test box is not being used, perform the following step.

-- Remove the Engine Control Module (ECM) -J623-. Refer to appropriate Repair information.

-- Using a multimeter, check the Exhaust Gas Temperature (EGT) Sensor 1 -G235- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector terminals for an open circuit.

Exhaust Gas Temperature (EGT) Sensor 1 -G235- electrical harness connector terminals	Engine Control Module (ECM) -J623- electrical connector terminals or test box socket
1	T94/20
2	T94/1
3	pin 30 of J496

Specified value: 1.5 Ω Max.

If the specification was not obtained:

-- Check the wiring for a short circuit to each other, Battery (+), or Ground (GND).

-- 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:

-- Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY 

-- Perform a road test to verify Repair.

If the DTC does not return:

Repair complete, Generate readiness code. Refer to READINESS CODE .

-- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:

-- Replace the Engine Control Module (ECM) -J623-. Refer to appropriate Repair information.

-- Assembly is performed in the reverse of the removal.

Final procedures 

After the Repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .