20 Most Recent 2003 Chevrolet Malibu - Page 4 Questions & Answers

The wire colour is Orange.

Ignition switch ? Key an lock cylinder or the electrical part ? The vehicle keeps running or you can't turn key to off ! Different thing's come into play depending on which is your problem ! If vehicle doesn't shut off (keeps running ) You need to know how it works ! An ignition switch isn't the same as back in the old days , it's a low voltage input to the BCM . Serial Data Power Mode On vehicles that have several control modules connected by serial data circuits, one module is the Power Mode Master, PMM. On this vehicle the PMM is the BCM. The PMM receives 3 discreet ignition switch signals to differentiate which power mode will be sent over the Class 2 Serial Data circuit. To determine the correct power mode the PMM uses the following circuits: ?€¢ Ignition 0

?€¢ Ignition 1 voltage

?€¢ Ignition 3 voltage

An you need a professional scan tool to deal with these problems ! Serial Data Messages The modules that depend exclusively on serial data messages for power modes stay in the state dictated by the last valid PMM message until they can check for the engine run flag status on the serial data circuits. If the PMM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is True, indicating that the engine is running, the modules fail-safe to RUN. In this state the modules and their subsystems can support all operator requirements. If the engine run flag serial data is False, indicating that the engine is not running, the modules fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle. Discrete Ignition Signals Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid PMM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, battery positive voltage, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

yeah my problem is the same the shifter has to sometimes be imunipulated to assure its in park or the ignition will not turn all the way off leaving a weak or dead battery the following day. i would play with the shifter to be sure its in park all the way

Is your tach (if you got one) or speedometer. jumping or bouncing? Check engine light? If so i would be suspect of vehicle speed sensor.

You have to change the fuel line vent valve. It can be called similar things and be in different places depending on the type of vehicle.

I have to ask, how long since a tune-up? Are there any applicable trouble codes? To check codes, yourself, at the least, you need an obd2 code reader. Check your security system. When it stalls, leave the key in the on position, if the security lamp on the dash does not start flashing, the passlock system is not the problem, according to my info.

Check wire harness between drivers side door and body between door hinges, maybe split wire in harness.

Your model does not use an expansion valve. It has an orifice tube in one of the metal lines that converts the gas to liquid.If the orifice tube is blocked it would be at the edge of the frost.Could also be a restricted air flow thru the radiator or the evap core inside the car.

Those had a problem with coolant getting sucked in due to a bad design . Gm is aware of the problem. You might check with dealer on alternate throttle body.

check the cat converter is not blocking the exhaust and upsetting the oxygen sensor readings

Make sure the electronics under the hood are dry or spray them down with WD-40. Also make sure you have no water in your fuel tank. The engine needs fuel compression and spark to fire. If it doesn't turn over-fix that. If it turns over but doesn't fire could be coil pack damage from the water or water in the gas.

Go to a different mechanic

Pull (and replace) the spark plugs and turn the engine over to expel any water in the cylinders. You may want to check the oil also. Crank case could be full of water. Might want to check the transmission fluid also.

But no question to ask apparently. Hence no answer.

If it is coming from the rear of the vehicle it is possibly the fuel pump. In that event you would hear it more clearly if you are close to the fuel tank as the pump is inside the tank. You should also hear it while the car is stopped with the engine running as the pump will be running normally. If there is no noise from that area it will not be the pump. If it is a grinding noise from the rear (and you have rear disc brakes)you may have a stone or other hard debris caught and moving around between the metal protection plate that sits behind the disc and the disc itself on one of the rear brake assemblies. Obviously if the noise appears when the car is completely stopped it will not be that. If coming from the front, you don't mention if the noise occurs when the car is sitting with the engine running or only when you are driving the car. If it is apparent when the car is sitting with the engine running, then open the bonnet and see if you can locate the source of the noise in the engine bay. If there is no noise from the engine bay then rev the engine a few times and see if the noise appears. If not then it is not engine related. Also when driving the car check if the noise increases and decreases when you are speeding up and slowing down.

Those vehicles are notorious for intake and head gasket leaks, make sure coolant is topped up, check engine oil for contamination- could be t stat but don't think so

The speedometer is ran off a sensor in the trans. First thing is check the fluid . There should be a dip located on top of the trans. It might be way down in there. Should be colored red or yellow. Start the vehicle then check the dipstick, if low add fluid. Low fluid could cause it to slip and and not engage. If it's full , note the color of the fluid. Red is good, brown, not so good and black is bad. I'm talking about the color of the fluid, how many miles? Also did any particular gear go out first? Most trans . Failures begin with loss of reverse first. Not always but that could be a good indication. If fluid black and burnt trans,. Is shot. Smell the fluid to detect a burnt smell. Hopefully it was just low. But given the sparse info its hard to say. If full and red or brown also most likely an internal prob.

Your owner's manual may shed some light on the warning light. You may need to have the engine computer checked for codes to know where to start testing. So it may need to be towed to a shop.

If you are trying to locate some kind of water valve that routes the hot water to or away from the heater core, no such animal exists anymore. Hot water is always routed thru the heater core whether or not you are using the heater. The blend box under the dashboard has flappers that move to route air either thru the heater core, the A/C evaporator, or thru a bypass that routes around both. The blend box allows you to set temperature by adjusting the flappers. It also controls where the air goes; defroster vents, floor vents, or dash vents. If you are not getting heat, the problem is most likely that the blend box flapper is not operating correctly. This could be due to a sticky linkage, a bad vacuum motor, or a faulty control head. You could also have a clogged heater core, or a thermostat that is stuck open all the time. If you are getting heat and don't want it, the blend box flapper is also the most likely cause.