← Look into the faults of the GMC Yukon XL
Trouble code
P1631: possible causes and documented repairs — 2000–2006 GMC Yukon XL
No record of the 2000–2006 GMC Yukon XL states trouble code P1631. What follows is what the technical documents say. The technical documents say how to deal with 1 of its possible causes. They are listed by the number of matching records, most first.
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Causes the technical documents say how to deal with (1)
Passlock theft deterrent: starts then stalls / no-start with security lamp
No matching record (stated by the technical documents)
A magnet in the ignition cylinder produces a unique voltage across a Hall effect sensor in the ignition housing; the BCM and lock cylinder enable starting.
If the voltage matches the stored value, the BCM signals the PCM to enable fuel.
How to tell
- B2960
- P1631
- Security light
What to do
- A security lamp flashing after an attempted start means the fuel disable command is active.
- A scan tool parameter showing 'fuel system disabled' or similar indicates a Passlock issue.
- Monitor the Passlock Data Voltage for approximately one minute; the voltage value should not change by more than .02 volt.
- If the voltage does not change from 5 volts, check the ignition housing.
1 more step ·All steps, part numbers and sources (3 sources) →
Related symptoms, trouble codes and warning displays
What the technical documents state together with the faults above.
- Trouble code
- B2960
- Warning display
- Security light
Put together by FaultCrate from public records and technical documents. The cause and the repair are for the workshop to decide with the vehicle in front of it. Counts are records, not failure rates.