1. Powertrain Control Module (PCM) 2. Electronic throttle control 3. MAP sensor
4. Throttle Body under air inlet 5. Fuel pressure regulator 6. Intake Air Temp Sensor (IAT)
| Typical engine data sensor and control component locations on the GM 4.2 L engine. Click on number for a description. |
7. Exhaust Cam Actuator Solenoid
| A few related auto repair questions and answers. |
2004 GMC envoy trouble code p0410 A.I.R. System.
8. Secondary Air Injection (AIR) Diverter valve
| 12-19-10 where is the cam position sensor. |
Comments
| From the front of the truck, it is located on the passenger side front of the engine. Just below the valve cover. Number 9 above. |
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9. Exhaust Camshaft Position sensor
| 12-21-10 04 GMC envoy 4.2L can you tell me where is can find coolant below temperature sensor. |
| There is no such sensor. I am guessing that you have a check engine light with code P0128- coolant temp below thermostat regulating temperature. This code is cause by either low coolant level, or more likely- a bad thermostat. |
| 1-7-11 where is the throttle body |
| The electronic throttle body, or TAC is located at position 2 in the picture above. The large air intake runner with the word Vortec to the left needs to be removed to get to. |
| 3-12-11 WHERE ARE THE SPARK PLUGS AND THE PLUG WIRES |
| This engine does not actually have spark plug wires. They are spark plug boots. They are located under the ignition coils on top of the engine. The spark plugs are down in the valve cover under each coil under the air box on top of the engine. |
| 3-13-11 THANK YOU FOR THE ANSWER. DO THESE SPARK PLUG BOOTS HAVE TO BE REPLACED AND HOW OFTEN, AND WHAT KIND OF SPARK PLUGS WOULD YOU RECOMMEND FOR THIS ENGINE. |
| The boots are part of the coils. They do not need to be replaced for maintenance. I would recommend AC Delco spark plugs. |
| 3-13-11 getting trouble code for secondary air injection. Replaced valve and pump, light stayed off for 120 miles but came back on so then replaced primary oxygen sensor. Light went out for a day or two but then came back on with same code,secondary air injection. |
| You say you replaced the valve. Which valve. There are 2 diverter valves and 1 vacuum control valve / solenoid. O2 sensor would not cause AIR code. |
| 4-11-11 I'm HAVING A HESITATION WHEN YOU FIRST GIVE IT GAS , WHAT COULD THAT BE. |
| Most commonly, that problem is due to a dirty or excessive amounts of carbon inside the throttle body. A good cleaning will resolve most issues. You can check on this website to find out the proper cleaning procedure if you don't know how. Check your air filter too and replace if dirty. |
| 4-13-11 HOW DO YOU CHANGE THE EXHAUST CAMSHAFT POSITION SENSOR AS I'm GETTING A CODE FOR IT IN MY 03 TRAILBLAZER. |
| 6-17-11 Where is 1997278 evap valve located on 2002 trailblazer? |
| I think that part number is for the EVAP vent valve, and it is located underneath the vehicle, back by the gas tank, attached to a hose that leads to the EVAP canister. It is easiest to replace by getting the Trailblazer up in the air, either on a lift or on jack stands. There is one electrical connector on it, and one hose connection. It is usually retained to the bracket by a small, bendable metal tab that you can bend out to remove it and then bend it back in after the new one is on. For future reference, the other valve/solenoid for the EVAP system is the Purge Solenoid, and it is located up by the intake manifold. |
| 6-21-11 I have a 1999 Chevy Tahoe 5.7 and have a sensor wire without a home....it is a ROUND plug near thermostat housing and a DRK GRN /wht and a lt grn wire....cant figure out what sensor it goes to ???? ANY HELP WOULD BE GREATLY APPRECIATED !!!!! |
| 6-21-11 If the check engine light is not on, then it may just be an unused connector. Sometimes there are extra connectors depending on engine size, options, ETC. Look inside the electrical terminals. If they are rusted or dirty, then that means they were never plugged into anything in the first place. |
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| 7-22-11 I have '02 Bravada/idles very rough especially when A/C or heater is on/or stopped with vehicle in gear/all started when I disconnected battery to try to reset auto load level compressor/may have been coincidence/but idled and ran great until then |
| You may have a carbon buildup in the throttle. After a battery disconnect, then computer tries to reset the idle. If the is a lot of carbon, it cannot find a stable idle. A good cleaning may just be needed. |
| 8-2-11 i have a 2004 GMC envoy with a 4200 in-line 6 cylinder. It has rough idling and some times it stalls. How do i clean the throttle body and what part needs to be cleaned ? Or is that something else. |
| See link in last post above labeled "Carbon Buildup In The Throttle" for cleaning procedure. |
| 8-6-11 When i turn on the motor without the AC on it idles just fine ,but when i turn the AC on it turns off or the ac won't come on for a 2004 trailblazer LS with the 4.2 litre motor. |
4.2L Inline 6 Cylinder Sensor Locations
| 8-18-11 your website is great! Thank you for the information! |
| Thank you ! Come visit us again ! |
| 9-20-11 Hi,2004 envoy 4x4 SUV,the service 4WD light came on this morning and hasn't since. Any thoughts? This a Canadian truck. |
| Would need to know the code it set, but you could be looking at a 4WD switch problem, encoder motor, or possibly a transfer case control module. Any of these would need some diagnosing by an experienced technician. You could have an intermittent problem, since the light is off now, and could be ok for the time being. |
| 9-22-11 2003 Trailblazer EXT....the rear fan AC works intermittently...I can't find any bad switches so what could be causing this?? |
| It could be the rear blower motor itself, or a bad blower resistor which is bolted to the rear HVAC case. |
| 10-11-11 where is the o2 sensor located - thats the code getting from meter. |
| 11-2-11 I have a 4.2 ;when I put it in to drive it has a slight shake but when i put it in reverse it does not. After it warms up for about 10 to 15 min it goes away. |
| 11-8-11 A slight vibration? Well, that could be a bad engine mount, since the engine torques to the left in drive, and the opposite direction when in reverse. |
| 11-13-11 Rough Idle even after cleaning the throttle body. The idle is ok when the engine is cold, but worsens as the rpm drops as the engine warms. |
| You may have a problem with the valve in the cylinder head. Have seen several times a rough idle causing a slight misfire on one or more cylinders caused by the valves and valve seats not sealing. |
| 11-13-11 Thermostat for 2004 trailblazer is not the same the store says it should be. Is it the same one as Gmc stat? Or the change I heard about? Where the stat is separate from housing? |
| 11-14-11 Where is temperature coolant sensor located. |
| 11-14-11 Where is crank position sensor located. |
| The crank sensor is located on the drivers side of the engine block as seen either though the wheel well or from under the truck. |
| 11-25-11 i've located the MAP Sensor....how do i release the clips to replace it. |
| 11-25-11 Pinch the little tabs carefully and pry up on sensor with a small screwdriver. Be careful, they break easily. |
| 12-14-11 If what you are saying is true and that the Vortec inline 6 has no coolant temperature sensor then why does auto zone sell one ?Duralast/Coolant Temperature Sensor for your 2004 GMC Truck Envoy 4WD 4.2L SFI DOHC 6cyl. Price: $29.99 Please help me before i spend money. |
| Don't see anywhere in these comments anyone saying that there is not a coolant temperature sensor. |
| 12-25-11 Where is the engine temperature sensor located on a GM 4.2 liter engine? |
| 12-31-11 I think the coolant temperature sensor is located on the left side of the engine. You can see it through the wheel well opening. |
| 1-2-12 Have a 03 GMC Envoy were can the knock sensor be located? |
| 1-11-12 Where is the oil sending unit located on the 04 Trailblazer 4.2L 6cyl? I have been told several things, on top of the block and down beside the oil filter. Which is correct? |
| That depends on which engine you have in your GMC Envoy. On the V8, they are located under the intake manifold. On the 4.1L straight 6 cylinder, they are on the drivers side of the block just above the oil pan. One near the front of the engine, one near the back. |
| The oil pressure sender is located on the oil filter housing. |
| 1-20-12 Where are the oxygen sensors located on the 2003 GMC Sierra 4.8 v8 4wd 1/2 ton pickup. |
| 1-21-12 2004 GMC Envoy XUV idle very hard at around 500 rpm then feels like engine is shaking under hood feels like it is trying to get exhaust out or something. Exhaust coming out very white smoke. |
| 1-23-12 Olds Bravada..Where is the camshaft position sensor located?Please help |
| Sounds like it is running very rich, like a stuck open fuel injector. |
| 2-5-12 My 2002 envoy service engine light comes on plus reduce power like comes on also and shuts off. |
| 2-6-12 I have the same issue...2002 envoy service engine light comes on then reduced power...npow my battery is drained and nothing...wont start or take a charge,,,maybe battery too dead for system? |
| Common is that the throttle is full of carbon and needs to be cleaned out. |
