P0A87 code meaning
14 Volt Power Module Current Sensor A Circuit Range/Performance
Powertrain system Generic code P0Axx codes Check engine light
What P0A87 means
This code means the current sensor of the 14 V power module (DC/DC converter, GM: APM) delivers values that are electrically valid but implausible. GM's 2016 eAssist tables (hybrid control processor HPC1) describe a stuck-in-range test: once per key cycle, while the high-voltage contactors are open and then move to precharge, the converter should be off, so the averaged input current must be near zero. If the average is 0.50 A or more, P0A87 sets as a Type B code, so the MIL comes on after two failed trips. The test is skipped while P0A88 or P0A89 is active. Unlike those circuit low/high codes, the wiring is usually intact here; a sensor with offset drift is the typical finding.
P0A87 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor1 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P0A87
- MIL on after two drive cycles
- Usually no driveability change
- Possible reduced 12 V charging if the converter is limited
Common causes of P0A87
- Most likelyCurrent sensor zero-point drift inside the power module
- PossibleConverter actually conducting current when it should be off (internal module fault)
- Less likelyGround or reference fault distorting the sensor signal
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pm14v current sensor aWiring harnessDcdc converter
What each part of P0A87 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A | Area: hybrid propulsion. |
| 87 | The exact fault in that area. |
What to do next
- Note P0A87 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 P0A87
What does P0A87 mean?
P0A87 means "14 Volt Power Module Current Sensor A Circuit Range/Performance". This code means the current sensor of the 14 V power module (DC/DC converter, GM: APM) delivers values that are electrically valid but implausible. It is a generic code, so it means the same on every make.
Is it safe to drive with P0A87?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0A87 fail an emissions test?
Yes, it can. P0A87 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 P0A87 to fix?
Difficulty: workshop only. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P0A87 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.