Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Code 19, Intermittent 7X Signal: Notes
The ignition control module sends a reference signal to the PCM 7 times per crankshaft revolution to indicate crankshaft position and RPM so that the PCM can determine when to pulse the ignition coils and control ignition timing. A 5-volt reference is supplied to the PCM from terminal "G" of the ignition module. This 5-volt reference signal is monitored by the PCM. 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 PCM misses at least 20 sync pulses within 4 minutes and 16 seconds.
- Determines if PCM recognizes a problem. If Code 19 does not set, problem is intermittent.
- When a resync occurs, engine will stumble. This step determines if component connections or circuit is faulty.
- Operating non-engine related components may generate electromagnetic interference which may cause a resync.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.