EGR Backpressure Transducer: Testing and Inspection

Fig. 157 BPT Test:

BACK-PRESSURE TRANSDUCER (BPT) VALVE
1. Plug one of the "A" ports.
2. Fill a length of clear tubing within 3 inches of ends.
3. Attach one end of tubing to "B" port of BPT valve.
4. Allow at least 2 inches of air between BPT Valve and water level (do not allow water to enter BPT Valve).
5. Loop tubing into a "U" shape.
6. Raise open end of tubing until the water level on open side of tubing is 50 mm (1.97 in.) higher than water level on the BPT side of tubing.
7. Apply vacuum to other "A" port.
^Vacuum should hold steady.
8. Slowly lower open end of tubing.
^As water level difference drops below 50 mm (1.97 in.) vacuum should bleed off.
If BPT fails above test replace valve.

EGR Valve Test:

EXHAUST GAS RECIRCULATION VALVE
Apply vacuum to fitting on valve.
^If the diaphragm does not hold vacuum or valve spring does not lift replace valve.

Fig. 170 Solenoid Test:

EGR SOLENOID FUNCTION TEST
Apply voltage to the solenoid terminals (positive (+) lead to the white wire of solenoid harness) and check air passages for continuity as shown above.
CAUTION: Reversing polarity will damage the solenoid.
^Replace solenoid if it fails above test.

Fig. 169 Solenoid OHM Test:

EGR SOLENOID RESISTANCE TEST
Check the solenoid resistance value with a suitable ohm meter as shown above.
Should be approximately 40 OHMS.
^Replace solenoid if it fails above test.