Why does my Honda CR-Z IMA light keep coming on?

Short answer: On a CR-Z, the IMA light often comes from cheap parts, not a dead hybrid battery. Owners traced it to the hybrid battery's cooling fan (code P1448), a brake pedal switch, or a weak 12-volt battery. Get the exact code read first; parts stores often scan for free. The car generally keeps driving, but if the power steering or charging lights join in, get it checked before a long trip.

Symptom: The IMA light comes on, often after long or hot drives, sometimes with auto-stop not working, a loud fan from behind the seats, or a wave of other warning lights.

What to check first

1. Get the code read. P1448 points to the IPU fan; a battery deterioration code points to the hybrid battery.
2. Listen behind the seats for a loud or uneven fan and make sure the vent isn't blocked.
3. Test the 12-volt battery and check its date.
4. If auto-stop has quit or the light comes on when braking, have the brake pedal switch checked.
5. Run your VIN at nhtsa.gov/recalls.

Likely causes

1. IPU battery cooling fan. IMA is Honda's name for the hybrid assist system. IPU is the box behind the seats that holds the hybrid battery, and it has a small cooling fan. Owners report code P1448 points to that fan, especially in hot weather.
2. Brake pedal switch. The auto-stop feature reads a switch at the brake pedal. A worn one can set an IMA warning.
3. Weak 12-volt battery. If the small battery can't hold the right voltage, owners say the fan and IMA system act up.
4. Hybrid battery losing capacity. An older nickel-metal hydride (NiMH) battery can set a battery deterioration code. Some owners rejuvenate it, which means slowly charging and balancing the cells with a special charger.

What it usually costs

One owner in a related thread said a New Zealand dealer charged about $1,400 for the IPU fan. Owners who replaced the fan or brake switch themselves didn't post parts prices.

Is it safe to keep driving?

With just the IMA light, owners kept driving and the gas engine still moves the car. If the power steering, ABS or charging lights come on too, the electrical system may be struggling; get it checked before you rely on it.

DIY or shop?

Reading codes, the 12-volt battery and the brake switch are DIY jobs. The fan sits by the hybrid battery; if you're not comfortable around high-voltage parts, have a shop do it. Hybrid battery rejuvenation is for experienced DIYers only.

Recalls, bulletins and complaints in plain words

• Recalls: NHTSA lists 3 recalls for the CR-Z in these years. One, 11V458000, covers some 2011 manual-transmission cars: if the engine stalls with the brake pedal released, the electric motor could make the car move. None covers the IMA fan. Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 13 keyword-matched complaints for Honda CR-Z 2011–2016 (of 68 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-31; keywords: ima, hybrid, battery, fan, loss of power) (NHTSA returned no data for 1 model-year queries). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In Check IMA light on Reddit r/crz, a 2014 CR-Z with 83,000 miles had the IMA light on and off with a loud whooshing from the fan. The Honda dealer's report showed P1448 for the IPU fan, but the fan passed their tests. The light came back after longer drives, and the owner was weighing replacing the fan anyway.
• In IMA/IPU fan problem(ᵕ °ㅁ° ).ᐟ.ᐟ.ᐟ on Reddit r/crz, a 2012 owner in Florida had the IMA light come on, followed by nearly every other warning light: check engine, traction control, ABS, charging and power steering. Their scan pointed to the IPU fan, and they ordered a replacement to fit themselves.
• In IMA light turns on ONLY after long drives on Reddit r/crz, the IMA light only came on after long drives. A mechanic saw an IMA alert once or twice and said the 12-volt battery was a little low but still in range. Members linked the light to the auto-stop system.
• In Safe to drive with IMA light on? on Reddit r/crz, several CR-Z owners compared notes: one pulled the code with a phone app and found a brake-pedal switch, another said a parts store scanned it for free, and another said rejuvenating the hybrid battery kept the light off for over a year.

Quick tip

Don't let anyone quote you a hybrid battery off just the light. On these cars the fan and the brake switch are common, and both are cheap compared with a pack.

Vehicle focus: Honda CR-Z, 2011-2016.

Safety / mechanic note

High-voltage parts and loss of power steering are safety items. Verify with a mechanic.