Jump-Start the Car

If your Honda Insight won’t power up and the dash is dark, the 12-volt battery in the engine bay is usually flat. Jump-starting brings the car’s electronics back online so the system can start. Because this is an IMA mild hybrid, you connect only to the 12-volt battery under the bonnet — never the orange high-voltage cables. Here is the safe way to do it.

Before you start

• You jump only the small 12-volt battery in the engine bay — not the IMA hybrid battery. Never touch the orange high-voltage cables.
• You need another 12-volt vehicle (not a 24-volt truck) or a 12-volt jump pack, and jumper leads in good condition.
• Do not jump-start a battery that is cracked, frozen or leaking. Wear eye protection, keep sparks away, and make sure the cars are not touching.

How to jump-start the car

1. Park the donor vehicle close enough for the leads to reach, without the two cars touching, and switch off both engines.
2. Connect one red (+) clamp to the Insight’s positive (+) terminal, and the other red clamp to the donor battery’s positive (+) terminal.
3. Connect one black (−) clamp to the donor battery’s negative (−) terminal, and the final black clamp to a solid, unpainted metal earth point on the Insight’s engine — not to the flat battery’s − terminal. This keeps any spark away from the battery.
4. Start the donor car and let it idle for a few minutes.
5. Start the Insight. Once it is running, remove the leads in the reverse order of connection: the Insight earth clamp first, then the donor −, then the donor +, and finally the Insight + clamp.
6. Keep the Insight running, then drive it for at least 20 minutes (not just idling) so it can recharge the 12-volt battery.

If it still won’t start

If the Insight will not power up after a good jump-start, or it powers up and then dies when you remove the leads, the 12-volt battery has probably failed internally — it is what boots the car’s computers and closes the hybrid contactors. Stop and have the 12-volt battery and charging circuit tested rather than trying repeatedly; if it needs replacing, see how to disconnect and reconnect the battery. Do not attempt to charge or work on the IMA high-voltage battery yourself — that is a dealer job.

Frequently asked questions

Does jump-starting the Insight charge the hybrid battery?

No. You are only reviving the ordinary 12-volt battery so the car can power up and start. The IMA hybrid battery is a separate high-voltage system and is not jump-started — and you must never touch its orange high-voltage cables.

Why connect the earth lead to the engine, not the battery?

A flat battery can give off flammable gas. Making the final negative connection to a metal earth point on the engine, away from the battery, keeps any small spark clear of that gas.

The car still won’t start after a jump — what now?

Stop and have it checked. A 12-volt battery that won’t hold a jump has usually failed internally, and on a hybrid the 12-volt battery must be healthy for the car to boot and start. A workshop can test the 12-volt battery and the charging (DC-DC) circuit quickly.

If a warning light stays on after you get going, you can look up what the specific dashboard symbol or fault code means on autodtcs.com.