Q: Car cranks over but won't start - 2004 Nissan Sentra

asked by on

Put an obd2 chip in a while back which leads to believe its the computer ecm, no coils are getting spark, all fuses and relays are good, just replaced fuel sending unit, but cant hear the pump kick on when turning the key.

My car has 182000 miles.
My car has an automatic transmission.

If the fuel pump is not "whirring" momentarily when you turn the key "on", either the pump is not receiving power or it’s non-functional. You might try probing the fuel pump harness for 12 volts at moment key is turned "on". If you do find that there is no power being supplied to the pump and there is also no power to the ignition system that would seem to suggest a "global" fault, in the ECM for instance, but the ECM is only one possibility (there are also relays involved).

The ECM has a self diagnostic which potentially could have set a DTC (Diagnostic Trouble Code) and so you should use a code scanner to see if such outputs exist (or were set). You might also try removing the chip you added and then "re-setting" the computer by disconnecting the battery negative terminal for 5-10 minutes.

If simple tests such as that just described do not work out for you, by all means contact YourMechanic and a mobile expert will be dispatched to diagnose this no start condition for you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Car cranks over but won't start - 2004 Nissan Sentra

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Windshield wipers move slow and get stuck

A few different items can cause the windshield wipers to work slow. The most common causes are the windshield motor beginning to fail, poor electrical connection at the windshield motor, or high resistance at the wiper motor. A qualified technician...

Q: 07 xterra cranks but wont always start. sometimes starts and shuts off immediately. sometimes just cranks and cranks

The best way to diagnose a problem like this is to play with certain components and attempt to replicate the issue. Components that could be causing these symptoms are the fuel pump, fuel filter, a number of solenoids and sensors,...

Q: Car stalls when idle but there is no check engine light.

You may need to have the computer monitored while driving to see if there is problems in the transmission or computer sensors? Some aftermarket scanners cannot access all systems and may need to have a more advanced scanner to do...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...