Three Needle Sweeps

NOTE: This test requires the use of a "socket box" type testing adapter.

1. With the engine off disconnect the EDS control unit. Check the resistance between sockets 3 and 10 of the testing adapter with the air flow sensor in the idle and fully open position. If the reading is approx. 50 - 200 Ohms in idle position or approx. 560 Ohms - 1.1 kOhms in the fully open position, proceed with step 2. If the values are not read, check for and repair any open circuits. If none are found, check air flow sensor plate for dirt accumulation and binding. Clean or replace the air flow sensor as needed.
2. With the engine off, the ignition on, and the EDS control unit connected, measure the voltage between sockets 3 (-) and 10 (+), and between sockets 3 (-) and 24 (+) of the test adapter. Voltage readings should be as follows:


TEMPERATURE RESISTANCE VOLTAGE


20°C 2500 OHMS 3.85 VOLTS
30°C 1700 OHMS 3.47 VOLTS
40°C 1180 OHMS 3.05 VOLTS
50°C 833 OHMS 2.63 VOLTS
60°C 600 OHMS 2.22 VOLTS
70°C 440 OHMS 1.85 VOLTS
80°C 327 OHMS 1.5 VOLTS
90°C 243 OHMS 1.22 VOLTS
100°C 185 OHMS 0.99 VOLTS

3. If the readings agree with the above table, system is ok, and the test is complete. If the readings do not agree with the above table, replace the EDS control unit.

NOTE: If the air temperature sensor has been removed, also perform the tests outlined under "NINE NEEDLE SWEEPS".