U3024 code meaning
Control Module Input Power Circuit B - Ignition Input On/Start Circuit Correlation
What U3024 means
U3024 is the same plausibility test as U3023, but against the module's second battery feed, B: with the key in run or start, feed B and the switched ignition input should show about the same voltage, and a lasting gap points to a fault on one of the two paths. The code only makes sense on modules with two permanent feeds plus an ignition line. No manufacturer documents U3024 publicly. For guidance, GM's 2025 tables describe the A variant in engine and transmission modules: battery present, run/crank active, starter not engaged, and a difference above 3 V in most of 50 samples. If only U3024 is stored and not U3023, feed B itself is the more likely culprit, since a missing ignition signal would upset both comparisons. Effects depend on what feed B powers inside the module.
U3024 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U3024
- Warning lamp or message, depending on the module
- Loss of functions supplied through feed B
Common causes of U3024
- Most likelyBlown fuse or damaged wire on battery feed B
- PossibleRun/crank relay or ignition wire delivering too little voltage
- PossibleLoose or corroded pin for feed B in the module connector
- Less likelyFaulty voltage sensing inside the module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Module power bIgnition input
What each part of U3024 means
| U | Network system: communication between the control modules (CAN bus). |
| 3 | Reserved range, usually generic. |
| 24 | The exact fault in that area. |
What to do next
- Note U3024 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 U3024
What does U3024 mean?
U3024 means "Control Module Input Power Circuit B - Ignition Input On/Start Circuit Correlation". U3024 is the same plausibility test as U3023, but against the module's second battery feed, B: with the key in run or start, feed B and the switched ignition input should show about the same voltage, and a lasting gap points to a fault on one of the two paths. It is a generic code, so it means the same on every make.
Is it safe to drive with U3024?
U3024 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U3024 fail an emissions test?
U3024 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U3024 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will U3024 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.