P263A code meaning
MIL Control Circuit Low
What P263A means
P263A means the engine module has found the line that switches the malfunction indicator lamp shorted to ground. GM checks it while the low-side driver is off: if the voltage stays low with an impedance to ground of about 0.5 ohm, the lamp control is faulty; the 2014 tables need 50 of 63 samples at 50 ms intervals, the 2019 tables a single sample, with run/crank voltage of at least 11 V and remote start inactive. GM files it as Type B but marks it no MIL, which makes sense because the lamp itself is the affected part; some controllers also log P0650. GM preliminary information PIT5391 lists P263A and P263B among codes left behind when ignition 1 voltage drops out through a KR73 relay or terminal fault on 2014–2016 trucks. A permanently lit lamp is the main symptom.
P263A at a glance
- Check engine lightUsually not
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P263A
- Engine warning lamp lit permanently
- Code stored even though the lamp cannot report it reliably
Common causes of P263A
- Most likelyMIL control wire chafed and touching ground
- PossibleLoss of ignition 1 voltage via main relay or fuse block terminal
- Less likelyFaulty lamp input in the instrument cluster
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
MIL lampInstrument clusterWiring harness
What each part of P263A means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 6 | Area: computer (engine control module) and output circuits. |
| 3A | The exact fault in that area. |
What to do next
- Note P263A and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P263A
What does P263A mean?
P263A means "MIL Control Circuit Low". P263A means the engine module has found the line that switches the malfunction indicator lamp shorted to ground. It is a generic code, so it means the same on every make.
Is it safe to drive with P263A?
P263A does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P263A fail an emissions test?
Yes, it can. P263A is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P263A to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will P263A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.