Exhaust Gas Recirculation: Testing and Inspection

Rotating Rear Wheels:

- Hoist vehicle so that rear wheels rotate freely.
- Set M/T or A/T in "Neutral" and transfer in "2H".
- Start engine, release parking brake lever and check that rear propeller shaft (tires) is turning.
- If not, perform following check with one rear tire locked and the other turned by hand.


WARNING: Make sure that M/T or A/T is set to "Neutral" position for this check. If it is set to any other position, rear tires will turn at high speed and a very dangerous situation may occur.

Comp. Loc:

- When engine is cool (coolant temperature is below 55°C, 131 °F), race engine and check that EGR valve diaphragm is not operating in this state, by touching diaphragm with finger.


CAUTION: If EGR valve is hot, it may be necessary to wear gloves to avoid burning fingers.

Movement Of EGR Valve Diaphragm:

- Warm up engine to normal operating temperature and race it after warming up. Then check to be sure that diaphragm moves toward 1 in figure at the left during acceleration and toward 2 during deceleration.

- If EGR valve fails to operate properly, check vacuum noses, EGR valve, EGR modulator, EGR SV valve, wire harness and ECM.
- Keep engine running at idle speed and open EGR valve by hand, and engine should either Stop or reduce its speed. If neither occurs, EGR passage is clogged. Clean it.