Test Cc - Wide Open Throttle
- Use only VOM/DVOM, not STAR tester, for this step. Turn key off and wait 10 seconds. Set DVOM on 20-volt scale. Connect DVOM negative test lead to STO at SELF-TEST connector and positive test lead to positive battery terminal. Install a jumper wire between STI and signal return at SELF-TEST connector. Perform KEY ON/ENGINE OFF SELF-TEST until end of CONTINUOUS SELF-TEST codes (DVOM reads zero volts). Depress and release throttle while watching DVOM reading. If reading did not change to a high voltage, depress throttle to WOT position and release. If STO voltage does not go to high reading, go to TEST HH - NO CODES/CODES NOT LISTED , step 15). Leave test equipment hooked up. If reading changes to high voltage, remain in OUTPUT STATE CHECK and go to next step.
- Turn key on, leaving engine off. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box and connect ECA to box. Place A/C switch on A/C position and set DVOM on 20-volt scale. Connect DVOM positive test lead to test pin 37 and negative test lead to test pin 54. Depress and release throttle several times while watching DVOM. If A/C clutch output cycles, EEC-IV system is okay. Check A/C system operation. If A/C clutch output does not cycle, remove jumper wire and go to next step.
- Turn key off and wait 10 seconds. Set DVOM on 200-ohm scale. Disconnect WAC relay and measure relay resistance. If reading is less than 50 ohms or more than 70 ohms, replace WAC relay and repeat QUICK TEST . If reading is between 50 and 70 ohms, connect WAC relay and go to next step.
- Turn key on, leaving engine off. Set DVOM on 20-volt scale. Connect DVOM positive test lead to VPWR circuit and negative test lead to ground. Measure VPWR voltage at WAC relay. If reading is less than 10.5 volts, repair open in harness and repeat QUICK TEST . If reading is 10.5 volts or more, go to next step.
- Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Set DVOM on 200-ohm scale. Measure resistance between test pin 54 and WAC circuit at relay connector. If reading is 5 ohms or more, repair open in harness and repeat QUICK TEST . If reading is less than 5 ohms, go to next step.
- Turn key off and wait 10 seconds. Leave breakout box installed and ECA disconnected. Set DVOM on 200,000-ohm scale. Measure resistance between test pin 54 and test pins 40, 46, and 60. If any reading is less than 10,000 ohms, repair short to ground and repeat QUICK TEST . If all readings are 10,000 ohms or more, go to next step.
- Turn key off and wait 10 seconds. Leave breakout box installed, ECA disconnected, and DVOM on 200,000-ohm scale. Disconnect WAC solenoid. Measure resistance between test pin 54 and test pins 37 and 57. If reading is 10,000 ohms or more, replace ECA and repeat QUICK TEST . If reading is less than 10,000 ohms, repair short to power and repeat QUICK TEST .
- Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Set DVOM on 20-volt scale. Measure voltage between test pin 10 and 40. If reading fluctuates from 4.0 to 10.5 volts as A/C switch is cycled, replace ECA and repeat QUICK TEST . If reading does not fluctuate, go to next step.
- Turn key off and wait 10 seconds. Set DVOM on 200-ohm scale. Measure resistance between ACC test pin 10 and A/C clutch. On 2.3L OHC/EFI engine equipped trucks, also measure resistance between test pin 24 (ACD) and A/C demand switch. If any reading is 5 ohms or more, repair harness and repeat QUICK TEST . If all readings are less than 5 ohms, EEC-IV is okay. Check A/C system.