Tab System Test (Code 46)
- Verify proper vacuum line routing to the TAB solenoid and to the bypass valve. If not correct, repair faulty routing and repeat Quick Test. If ok, proceed to step 2).
- Disconnect vacuum line on bypass valve and cap off vacuum line. Turn ignition off and wait 10 seconds. Repeat Engine Running Test and record service codes. Check for code 46. If code 46 is present, EEC system is ok, check Thermactor system. If code 46 is not present, proceed with test.
- Turn ignition off and wait 10 seconds. Disconnect TAB solenoid connector and measure solenoid resistance. If resistance is less than 50 ohms or greater than 100 ohms, replace TAB/TAD solenoid assembly and repeat Quick Test. If resistance is between 50 and 100 ohms, reconnect solenoid and proceed with test.
- Turn ignition off and wait for 10 seconds. Connect voltmeter negative lead to self-test output connector and positive lead to battery positive post. Turn ignition on. Run Quick Test until the completion of the Continuous Codes. Voltmeter will read 0 volts. Depress and release throttle. Voltage reading should increase. If voltage increased, leave voltmeter connected and proceed with test. If voltage reading did not increase, depress and release throttle again. If voltage still does not increase, perform Output State Not Functioning Test.
- Disconnect TAB connector. Connect voltmeter negative lead to circuit 190 and positive lead to TAB solenoid circuit 361. Depress and release throttle while observing voltmeter. If output cycles on and off (high to low voltage), replace TAB solenoid and repeat Quick Test. If output does not cycle on and off, proceed to step 6).
- Turn ignition off and wait 10 seconds. Disconnect processor and inspect both 60 pin connectors. Measure resistance of harness circuit 190 to ground. If resistance is less than 10,000 ohms, repair harness short and repeat Quick Test. If resistance is 10,000 ohms or more, replace processor and repeat Quick Test.