Top 20
2003 Chevrolet Impala Questions & Answers
2003 Chevy Impala cranks but won't start. Low voltage to fuel injector and misfire in cylinder 3 and no power to fuel pump.
cranks ok, but will not start
well he low voltage (non told) is from cranking the battery flat/low.
so charge the battery ;.
P0303 codes right? and no others?
power to the fuel pump happens only 3 ways
1: the priming action to pump key on for 1 to 2 seconds, as you can see that is a 2 person job. lacking huge long meter test leadss
2 cranking the pump runs only cranked.
3: engine running.,fully and sustained.
No engine told 3.4L or 3.8L. automatic I resume.
VIN derivative (1) for 3100 LG8 and 3400 LA1
Learn first that injectors are disabled if the pCM sees gross errors with spark, dead cmp , dead ckp or spark feed back dead.
to see that on a scan tool (real)
we use charged battery first.
then scan tool connected we crank for 10 full seconds , no longer.
release the key , not tuned off and see all DTC P03xx not just one.
see them all, and they all matter.
Lacking those events test all spark plugs for spark not just 1.
and test fuel pressure CRANKED a dead engine.
spec is, 3.4L (52-59?psi)
Why did I/P lights and heat stop working?
Are these the lamps not working?
Interior Lamps Dimming
The second group of interior lighting includes lamps which may be dimmed. This group uses a combination of class 2 controlled illumination and incandescent lamps:
• Ashtray lamp
• Door switches and window switches
• Fog lamp switch
• HVAC control head assembly
• Outside rear view mirror switches
• Radio
• Steering wheel controls
• Instrument panel cluster (IPC)
• Traction control switch
• Headlamp switch
• Hazard switch
• Heated seat switch
• The rear view mirror lamps
• Surveillance mode switch (SEO, 9C1/9C3)
The RH instrument panel (I/P) fuse block supplies battery positive voltage to both the coil and normally open switch contacts of the park lamp relay. When the body control module (BCM) energizes the park lamp relay, current flows from the park lamp relay switched contacts through the REAR PARK LP fuse to the I/P dimming switch. When dimming is selected, by moving the I/P dimming switch, all incandescent back lighting lamps (see schematics) and the BCM are provided with a variable voltage through the instrument panel lamp supply voltage #1 circuit. The incandescent back lighting lamps are then grounded at G201, G203 and G302. The BCM then applies a message signal to the class 2 circuit to the IPC and radio. The class 2 displays then dim to the level set by the I/P dimmer switch. When the I/P dimmer switch is moved from MIN to MAX, all class 2 displays and all incandescent back lighting respond from minimum intensity to maximum brightness.
Parade mode may be selected by manually turning on the park lamps during daylight conditions. The front park lamp circuit supplies voltage the HVAC assembly for a park lamp on input, and the display will become full bright. The BCM applies a message signal to the class 2 circuit to the IPC and radio commanding the displays to become full bright. The surveillance mode switch (SEO) overrides this feature.
Battery Rundown Protection / Inadvertent Power
The body control module (BCM) controls the lighting system through circuits that enable the park lamps, head lamps and fog lamps as well as the interior lamps. The BCM opens these enabling circuits 20 minutes after the ignition switch is turned OFF with no subsequent lamp switch activity. If the ignition switch is turned to any position other than OFF, or if a lamp switch is activated, during this 20-minute period, the timer will reset for another 20 minutes.
Dash lights an heat have nothing in common, two separate problems.
Hooking up a scan tool an checking for stored DTC'S -diagnostic trouble codes in the BCM would be first step in diagnostic procedures.
Interior Backlighting Inoperative
Step
Action
Yes
No
Schematic Reference: Interior Lights Schematics
1
Did you perform the Lighting System Diagnostic System Check?
Go to Step 2
Go to Diagnostic System Check - Lighting Systems
2
Turn the ignition switch to the RUN position.
Turn the door switch to the ON position.
Turn the headlamp switch to the HEAD position.
Do all of the interior lamps illuminate?
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 3
3
Is only one lamp inoperative?
Go to Step 4
Go to Step 5
4
Repair the open or high resistance in the inoperative lamp power supply or ground circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring System.
Did you complete the repair?
Go to Step 6
--
5
Important: Perform the set up procedure for the body control module (BCM). Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.
Replace the BCM. Refer to Body Control Module Replacement in Body Control System.
Did you complete the replacement?
Go to Step 6
--
6
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2
2003 Chevy impala. engine stalling after it's warm or idling. Also will sputter a lot and not start up again for hours
sounds like its being starved. check the fuel line and filter. also the fuel pump. could be the pump wnem it gets warmed up not giving pressure or the filter is blocked. same for the air filter. could also be too much air is in the mix broken vacuum line or gasket on manifold.. if any hissing sounds can be herd with engine running that is the sound of leaking air into engine. some times you cannot hear it or see it, you will need to spray carb cleaner over different areas if the engine sound changes or cuts out itt were the leak is.
03 impala is overheating and already changed the thermastat what should i check next
GM vehicles from 2003 to 2006 had instrument cluster problems were gauges showed wrong data , indicating overheating , wrong speed or no speed , low or no oil pressure etc.... Taking to a qualified repair shop that has a professional scanner that can view coolant temp. data to the PCM an from the PCM to the instrument cluster , rather buying parts the vehicle doesn't need . An trying to guess the problem instead of diagnose the problem . Your vehicle may not even be overheating ,if your just going by the temp gauge.
2003 impala stalls while driving and right after
If you have an engine light on you might ask autozone to read the code and tell you what's wrong. It could be that your spark plugs are worn out. If the spark plug gap is too great then that could cause stalls due to lack of ignition.
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