Diagnostic trouble code

P1570 — Battery Module Individual Voltage Problem (Honda IMA)

P1570Service soon — don't leave it for months

What it means in plain English

Specific modules inside your Honda IMA pack are reporting voltages the battery computer doesn't accept.

Honda's IMA pack is split into modules, and the battery computer watches each one. P1570 is set when individual modules report voltages outside the range the system expects — usually a spread between the strongest and weakest modules rather than one obviously dead cell. It is a pack-condition code, not a parts order. Honda stores a sub-code alongside it that narrows which measurement tripped, and reading that sub-code is the difference between a diagnosis and a guess.

Which Toyota and Lexus models this applies to

Honda hybrids using Integrated Motor Assist: Civic Hybrid, Insight, Accord Hybrid and CR-Z. IMA is a mild-hybrid system, so the symptoms differ from a Prius — the car was never able to drive on electric alone.

Possible causes

Plural on purpose. Any of these can produce this result — which is exactly why a code is not a diagnosis.

Genuine module imbalance from age — the usual cause on a pack past ten years.
One or more modules with high internal resistance dragging the pack's usable range down.
A pack that has been sitting, which lets the weakest modules drift furthest.
Restricted cooling airflow through the pack, which ages modules unevenly.
A battery condition monitor or voltage-sensing harness fault reporting a spread that isn't really there.
A previous repair that put mismatched modules into the pack.

What a professional diagnostic process should check

1Read the sub-code stored with P1570 — Honda uses it to narrow which measurement failed, and it is lost the moment the code is cleared.
2Module-level voltage and internal resistance across the whole pack, captured under load rather than at rest.
3Check the spread between the strongest and weakest modules, not just the pack total.
4Verify the battery cooling fan runs and that air actually moves through the pack.
5Inspect the voltage-sensing harness and connectors for corrosion and resistance.
6Confirm 12V battery health and charging voltage before blaming the IMA pack.
7Check for open Honda service bulletins and any remaining IMA warranty extension on the model year.

What you can safely do now

Ask for the sub-code and the module-level numbers, not just the P1570.
Check whether your model year is covered by a Honda IMA warranty extension — several were.
Note whether the car sat unused for a long period before the light appeared.
Keep driving it gently if it drives normally, and get it measured before the weather gets hot.

What not to do

Don't clear the code before someone has read the sub-code. Clearing it throws away the most useful thing on the scanner.
Don't accept "it's the IMA battery" without module numbers behind it.
Don't let anyone quote a Prius process for this pack — IMA is a different system with different modules.

When towing or urgent service is appropriate

Not normally a tow. An IMA car with a failing pack still drives on the engine. Tow it if the car won't start, if the check engine light is joined by charging-system warnings, or if you lose power assist.

Not sure which category you're in? Call 623-323-0737 and describe what the car is doing. That call is free and it might save you a tow — or a much bigger repair.

Do not replace parts based on a code alone

Do not replace parts based on a code alone. A diagnostic trouble code tells you which circuit or system reported a problem — it does not identify which component failed. The same code can be set by several different faults, and clearing it without a diagnosis just hides the evidence. This page is educational; your vehicle needs its own inspection before any repair decision.

P1570 — common questions

Can I still drive a Honda Civic Hybrid with P1570?

Usually yes. IMA assists the engine rather than driving the car, so a weak pack costs you fuel economy and some acceleration rather than mobility. Get it measured before summer — heat is what turns a slow decline into a failure.

Is P1570 the same as P0A7F?

They are related but not identical. P0A7F is the generic hybrid deterioration code; P1570 is Honda-specific and points at individual module voltages. They frequently appear together on the same car, and the diagnosis is the same either way — module-level numbers first.

Does a module swap fix P1570?

Sometimes, and only when the rest of the pack is genuinely healthy. If the spread comes from the whole pack ageing together, replacing the worst two modules buys months, not years. The measurements tell you which situation you're in.

Get P1570 diagnosed properly

Tell us the code, the year and model, and what the car is doing. We'll tell you what we'd check — and we won't quote a repair from a code.

Not sure what your hybrid needs? We'll work it out with you.

We come to you, test the pack, the 12V and the cooling, and you get a written quote before anything is decided. No obligation.

Call 623-323-0737 Schedule a repair