P1682

Ignition 1 Switch Circuit 2

Car Fault Codes Chevrolet Engine computer & electrical

Can you still drive? With care, short trips only

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 3 hours

Typical cost SAR 50 to 800

What it means

This is a Chevrolet (GM) manufacturer-specific code, and the same number can mean something different on other makes. The engine computer receives the ignition on signal through two circuits, and this code means the voltage on the second circuit does not match the first. It is usually linked to a weak fuse or connection in the feed, and it can cause stalling or a no-start.

Models covered: Chevrolet (GM) models, mainly around 2000–2007.

Symptoms4

Sudden engine stalling while driving in some cases.
Engine cranks but does not start at times.
Check engine light on, and gauges may flicker.
The code may be stored with no symptoms if the drop was brief.

Possible causes6

A blown or poorly seated fuse in the second ignition feed.
Corroded or loose terminals in the fuse block or engine computer connector.
A faulty electrical ignition switch or its connector.
A damaged wire or weak splice in the feed circuit.
A weak ground or low battery voltage.
An engine computer fault (rare).

How to diagnose5

Read the codes and note any voltage or communication codes.
Watch both ignition feed voltages on a scan tool if available and compare them while moving the key.
Check the engine computer feed fuses by measuring, not only by looking.
Inspect fuse block terminals and the computer connector for corrosion or heat marks.
Gently move the ignition key with the engine running and watch for stalling or a voltage change.

How to fix5

Replace the damaged fuse and fix the reason it blew, if any.
Clean or repair fuse block terminals and connectors.
Repair the damaged wire or weak splice in the feed.
Replace the electrical ignition switch if it is confirmed faulty.
Clear the codes, test starting and driving and confirm the code does not return.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

A fuse or connector cleaning is the low end, while an ignition switch or hard-to-reach wiring repair raises the cost.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Can this code make the engine stall while driving?

Yes. If the ignition feed to the computer drops even briefly, the engine can stall, so do not delay the check if the code appears with any stalling.

Why is looking at the fuse not enough?

A fuse can look fine but have poor contact or a corroded terminal in the block. Measuring with the engine running is more reliable.

Is the computer itself the problem?

Rarely. The computer detects the difference between the two circuits; the cause is usually a fuse, connector or the ignition switch.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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