Automatic Transmission

If, when performing tests on the various components controlled by the Emissions Control Unit (control unit output tests), the voltage to the particular component is not as specified (no voltage when there should be, or voltage when there should not be), check related inputs listed below first.
If none of the related systems are found to be at fault, then try replacing the Emissions Control Unit with a known good unit and retest.


FREQUENCY VALVES A AND B (B13 Grn/Blk)

1. Check ignition power source and ground circuits.
2. Check for ignition coil signal.
3. Check the A/T shift position signal.
4. Check vacuum switch A.
5. Check vacuum switch B.
6. Check speed pulser.
7. Check coolant temperature (TW) sensor.
8. Check the intake air temperature (TA) sensor.
9. Check oxygen sensor.


FEEDBACK CONTROL SOLENOID VALVE (B4 WHT/YEL)

1. Check ignition power source and ground circuits.
2. Check for ignition coil signal.
3. Check the A/T shift position signal.
4. Check vacuum switch B.
5. Check coolant temperature (TW) sensor.


FREQUENCY SOLENOID VALVE (B5 BLU/RED)

1. Check ignition power source and ground circuits.
2. Check battery power source.
3. Check for ignition coil signal.
4. Check the A/T shift position signal.
5. Check speed pulser.
6. Check coolant temperature (TW) sensor.
7. Check the A/C switch signal.


IDLE BOOST SOLENOID VALVE (B4 YEL/WHT)

1. Check ignition power source and ground circuits.
2. Check for ignition coil signal.
3. Check the A/T shift position signal.
4. Check vacuum switch A.
5. Check speed pulser.
6. Check the intake air temperature (TA) sensor.
7. Check the A/C switch signal.


AIR SUCTION CONTROL SOLENOID VALVE (B9 BLU/YEL)

1. Check ignition power source and ground circuits.
2. Check for ignition coil signal.
3. Check vacuum switch A.
4. Check speed pulser.
5. Check coolant temperature (TW) sensor.
6. Check the intake air temperature (TA) sensor.


ANTI-AFTERBURD CONTROL SOLENOID VALVE (B10 WHT/BLU)

1. Check ignition power source and ground circuits.
2. Check the A/T shift position signal.
3. Check coolant temperature (TW) sensor.


CRANKING LEAK SOLENOID VALVE (B11 BLU/RED)

1. Check ignition power source and ground circuits.
2. Check for starter signal.
3. Check for ignition coil signal.
4. Check speed pulser.
5. Check coolant temperature (TW) sensor.
6. Check the intake air temperature (TA) sensor.


PRIMARY SLOW MIXTURE CUT-OFF SOLENOID VALVE (B12 GRN/RED)

1. Check ignition power source and ground circuits.
2. Check for ignition coil signal.
3. Check the A/T shift position signal.
4. Check vacuum switch A.
5. Check vacuum switch B.
6. Check speed pulser.
7. Check coolant temperature (TW) sensor.


A/C IDLE BOOST SOLENOID VALVE (B1 RED)

1. Check ignition power source and ground circuits.
2. Check for ignition coil signal.
3. Check vacuum switch A.
4. Check speed pulser.
5. Check coolant temperature (TW) sensor.
6. Check the A/C switch signal.


EFE HEATER RELAY (A4 BLU)

1. Check ignition power source and ground circuits.
2. Check for ignition coil signal.
3. Check coolant temperature (TW) sensor.