Code 19 - Intermittent 7X Signal (2.3L): Notes

The ignition control module sends a reference signal to the ECM 7 times per crankshaft revolution to indicate crankshaft position and RPM so that the ECM can determine when to pulse the ignition coils and control ignition timing. A 5-volt reference is supplied to the ECM from terminal "G" of the ignition module. This 5-volt reference signal is monitored by the ECM. The ignition module pulls this signal low based upon 7X reference pulses. The seventh pulse is used for crankshaft position (sync) reference. Code 19 is set if the ECM misses at least 20 sync pulses within 4 minutes and 16 seconds.

1. This step determines if the ECM recognizes a problem. If it doesn't set Code 19 at this point, the problem is intermittent.
2. When a 7X resync occurs, engine stumble also occurs. If a component connection or circuitry is at fault, engine stumble may be induced by wiggling the circuit or connection.