Code 23 - M/C Solenoid Circuit Low
Code 23 indicates a continuous low voltage at ECM terminal No. 14 instead of a rising and falling voltage caused by the M/C solenoid cycling. This condition may be caused by an open in the solenoid circuit or a ground on the ECM side of solenoid. An open will cause a full rich condition and a short to ground will cause a full lean condition.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- 1) This test checks for a complete circuit from the battery to the M/C solenoid dwell lead. Reading should be battery voltage. Battery voltage means there might be an open circuit between the dwell connector and ground. No voltage could be an open between connector and battery or a ground on ECM side of the M/C solenoid.
- 2) This test checks for voltage on the Pink/Black ignition source wire. Test light should light between the ignition source to ground.
- 2A) This test checks for an open in the solenoid to ECM circuit. A normal circuit would read about battery voltage at ECM terminal No. 14.
- 3) This step determines whether fault is in M/C solenoid or a ground in circuit to ECM or ECM. A light would indicate a ground in circuit to terminal No. 14 or a faulty ECM.
- 3A) This step determines if the M/C solenoid is shorted. A good solenoid will have over 10 ohms resistance. A shorted solenoid could cause the ECM to fail.
- 4) This checks for ground in wire to ECM terminal No. 14. If it is grounded, light will stay on.