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.
Fuel Pump Electrical Circuit
2000 Saturn LS AutomaticSECTION Fuel Pump Electrical Circuit
- Perform OBD system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
- Connect scan tool. Turn ignition on. Using scan tool, command fuel pump relay on and off. If fuel pump turns on and off, check for intermittent problem. See appropriate TROUBLE SHOOTING - NO CODES article. If fuel pump does not turn on and off, go to next step.
- Using scan tool, command fuel pump relay on and off. If fuel pump relay clicks, go to step 9 . If fuel pump relay does not click, go to next step.
- Turn ignition off. Disconnect fuel pump relay located in underhood fuse/relay center. Turn ignition on. Using test light connected to ground, probe fuel pump relay control circuit. Using scan tool, command fuel pump relay on and off. If test light turns on and off, go to next step. If test light does not turn on and off, go to step 6 .
- Connect test light between fuel pump relay control circuit and fuel pump relay ground circuit. Using scan tool, command fuel pump relay on and off. If test light turns on and off, go to step 21 . If test light does not turn on and off, go to step 24 .
- If test light remains illuminated, go to next step. If test light does not illuminate at all, go to step 8 .
- Disconnect PCM. Check fuel pump relay control circuit for short to voltage. Repair as necessary. After repairs, go to step 29 . If circuit is okay, go to step 28 .
- Disconnect PCM. Check fuel pump relay control circuit for open or short to ground. Repair as necessary. After repairs, go to step 29 . If circuit is okay, go to step 22 .
- Turn ignition on. If fuel pump operates continuously, go to next step. If fuel pump does not operate continuously, go to step 11 .
- Turn ignition off. Disconnect fuel pump relay. Turn ignition on. If fuel pump operates continuously, go to step 23 . If fuel pump does not operate continuously, go to step 27 .
- Check F/P-INJ fuse (20-amp) located in underhood fuse relay center. If fuse is open, go to next step. If fuse is okay, go to step 14 .
- Disconnect fuel pump harness connector from rear body harness connector. Check fuel pump power supply circuit for short to ground between fuse and body harness connector. Repair as necessary. After repairs, go to step 29 . If circuit is okay, go to next step.
- Lower fuel tank. Check fuel pump harness for damage or grounded circuit. Repair as necessary. After repairs, go to step 29 . If harness is okay, go to step 20 .
- Turn ignition off. Disconnect fuel pump relay located in underhood fuse relay center. Turn ignition on. Using test light connected to ground, probe fuel pump relay ignition feed circuit at relay cavity. If test light illuminates, go to next step. If test light does not illuminate, go to step 25 .
- Connect fused jumper wire between fuel pump relay ignition feed circuit and fuel pump power supply circuit at relay cavities. If fuel pump operates, go to step 21 . If fuel pump does not operate, go to next step.
- Disconnect fuel pump harness connector from rear body harness. Check fuel pump power supply circuit for open or high resistance between fuel pump relay and rear body harness connector. Repair as necessary. After repairs, go to step 29 . If circuit is okay, go to next step.
- Check fuel pump ground circuit for open or high resistance between ground and body pass-through harness connector. Repair as necessary. After repairs, go to step 29 . If circuit is okay, go to next step.
- Check for poor connections at fuel pump harness to body pass-through harness connector. Repair as necessary. After repairs, go to step 29 . If connections are okay, go to next step.
- Lower fuel tank. Check fuel pump harness for damage, opens or poor connections. Repair as necessary. After repairs, go to step 29 . If harness is okay, go to step 26 .
- Reconnect all components. Install NEW F/P-INJ fuse (20-amp). Using scan tool, command fuel pump on. If fuse blows, go to step 26 . If fuse does not blow, check for intermittent problem. See appropriate TROUBLE SHOOTING - NO CODES article.
- Check for poor connections at fuel pump relay. Repair as necessary. After repairs, go to step 29 . If connections are okay, go to step 27 .
- Check for poor connections at PCM. Repair as necessary. After repairs, go to step 29 . If connections are okay, go to step 28 .
- Repair short to voltage in fuel pump power supply circuit. After repairs, go to step 29 .
- Repair open in fuel pump relay ground circuit. After repairs, go to step 29 .
- Repair fuel pump relay ignition feed circuit. After repairs, go to step 29 .
- Replace fuel pump. After repairs, go to step 29 .
- Replace fuel pump relay. After repairs, go to step 29 .
- Replace PCM. Perform PCM relearn procedures. After repairs, go to next step.
- Operate system to verify repair. If system operation is okay, testing is complete. If system operation is not okay, go to step 2 .
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra 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.