Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Code 16: Fuel Injector Circuit
- Turn ignition off. Remove ACG fuse (No. 15, 7.5-amp) fuse from underdash fuse box for 10 seconds to reset ECM. Check ECM for fault codes. If Code 16 is not present, problem is intermittent. Check for poor connections at ECM, fuel injectors, fuel injector resistor and wiring harness connectors. Test drive vehicle and retest.
- If Code 16 is present, start engine. Using a stethoscope, check for clicking sound at each injector. If injector does not click, turn ignition off. Disconnect 2-pin injector connector from affected injector. Measure resistance between injector terminals. If resistance is not 1.5-2.5 ohms, replace injector. If resistance is 1.5-2.5 ohms, go to next step.
- Turn ignition on. Measure voltage between fuel injector wiring harness connector Red/Black wire and body ground. If battery voltage is present, go to step 6. If battery voltage is not present, turn ignition off.
- Disconnect 8-pin connector at injector resistor. Turn ignition on. Measure voltage between Yellow/Black wire terminal (+) and body ground. If battery voltage is not present, repair open in Yellow/Black wire between injector resistor and main relay. If battery voltage is present, disconnect injector resistor connector.
- Measure resistance between terminal "E" and all other terminals. See Fig 1 . If resistance is not 5-7 ohms, replace injector resistor. If resistance is 5-7 ohms, repair open in Red/Black wire between 2-pin connector and injector resistor.
- If battery voltage was present in step 3, turn ignition off. Reconnect fuel injector connector. Connect ECM Test Harness (07LAJ-PT3010A
) between ECM and ECM connectors. See Figure
. Turn ignition on. Check voltage between A23 (-) and following test terminals.
- Injector No. 1: A1 (+)
- Injector No. 2: A3 (+)
- Injector No. 3: A5 (+)
- Injector No. 4: A2 (+)
- Injector No. 5: A4 (+)
- Injector No. 6: A6 (+)
If battery voltage is not present, repair open in wire between injector and ECM connector terminal A1, A2, A3, A4, A5 or A6. If battery voltage is present, replace ECM and retest.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.