Fuel System (VIN L)
- Before checking fuel system for a no-start condition, check ignition for adequate spark. Check for proper fuel pump pressure and capacity. See BASIC FUEL SYSTEM CHECKS.
- Turn ignition off. Install fuel pressure gauge. Using a fused jumper wire connected to battery voltage, jumper fuel pump test terminal. Turn ignition on. Listen for fuel pump operation and note fuel pressure gauge reading.
- If fuel pump operates and fuel pressure is okay, go to next step. If fuel pump does not operate, go to step 8). If fuel pump operates, but fuel pressure is not present, go to BASIC FUEL SYSTEM CHECKS.
- Remove jumper wire. Remove fuel pump relay. Connect test light between fuel pump relay connector Orange wire and Black/White wire terminals. If test light illuminates, go to next step. If test light does not illuminate, connect test light between ground and relay connector Orange wire terminal. If test light illuminates, check for open in Black/White wire. If test light does not illuminate, check for open in Orange, Pink or Red wire.
- Turn ignition off. Connect test light between relay connector Dark Green/White wire and Black/White wire. Turn ignition on. If test light illuminates for about 2 seconds, go to next step. If test light does not illuminate, check for poor relay connections. If connections are okay, replace fuel pump relay.
- Turn ignition off. Connect test light to ground. Backprobe PCM connector Dark Green/White terminal (fuel pump driver circuit). Turn ignition on. If test light illuminates for about 2 seconds, check for open in Dark Green/White wire. If test light does not illuminate, go to next step.
- Disconnect PCM connector. Using test light connected to battery voltage, probe PCM connector Dark Green/White wire terminal. If test light illuminates, check Dark Green/White wire for short to ground. If test light does not illuminate, check for faulty PCM connector or faulty PCM.
- Turn ignition off. Remove fuel pump relay. Using a fused jumper wire, jumper relay connector Orange wire terminals. Turn ignition on. Fuel pressure gauge should indicate fuel pressure. If fuel pressure is present, check for poor relay connection, open in Red wire to fuel pump test terminal or faulty fuel pump relay. If fuel pressure is not present, go to next step.
- Turn ignition off. Raise and support vehicle. Disconnect fuel pump connector at fuel pump. Connect test light between fuel pump connector terminals. Turn ignition on. If test light illuminates, replace fuel pump. If test light does not illuminate, check for open in Gray or Black wire fuel pump.
Courtesy of GENERAL MOTORS CORP.