Question about 2004 Chevrolet TrailBlazer

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On Board diagnostic system

Where is the Diagnostic link connector, (DLC) located? I have to take in my 2004 Chevy Trailblazer for the Vehicle emissions test and have to remove, (cover) for their techs to run diagnostics.

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  • ducati817 Sep 15, 2008

    Thank you so much!



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Under the dash on the drivers side. when you take it in they will do it for you. that is their job.

Posted on Sep 15, 2008


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Fuses controlling abs on 2005 ford taurus

Inspection and Verification
  1. Verify the customer concern.
  1. Verify the stoplamps operate correctly by pressing and releasing the brake pedal with the ignition switch in the OFF position. If the stoplamps do not operate correctly, refer to Section 417-01 . If the stoplamps operate correctly, proceed to the next step.
  1. Verify that the PRNDL operates correctly on the instrument cluster. If the PRNDL does not operate correctly, refer to Section 413-01 . If the PRNDL operates correctly, proceed to the next step.
  1. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart Mechanical Electrical
  • Wheel speed sensor ring
  • Hydraulic control unit (HCU)
  • Incorrectly inflated tires
  • Mismatched wheels or tires on vehicle
  • Base brake concern
  • Brake booster vacuum hose
  • Specified steering components, suspension components and tire size
  • Battery junction box (BJB) fuse(s):
    • 32 (40A)
    • 35 (20A)
  • Smart junction box (SJB) fuse 27 (10A)
  • Anti-lock brake system (ABS) module
  • Wheel speed sensors
  • Brake pedal position (BPP) switch
  • Brake fluid level switch
  • Wiring harness
  • Connectors or connections
  • Circuitry

  1. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
  1. If the concern remains after the inspection, connect the diagnostic tool to the data link connector (DLC) located beneath the instrument panel, and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
    • check that the program card is correctly installed.
    • check the connection of the data link connector to the vehicle.
    • check that the ignition switch is in the RUN position.
  1. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
  1. NOTE: The battery voltage must be greater than 9.4V for the self-test to operate correctly.
    Carry out the diagnostic tool data link test. If the diagnostic tool responds with:
    • CAN or ISO circuit fault; all electronic control units no response/not equipped, refer to Section 418-00 .
    • No response/not equipped for the ABS module, Go To Pinpoint Test A .
    • System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the self-test diagnostics for the ABS module.
  1. If the DTCs retrieved are related to the concern, go to the Anti-lock Brake System (ABS) Module Diagnostic Trouble Code (DTC) Index to continue diagnostics.
  1. If no DTCs related to the concern are retrieved, GO to Symptom Chart to continue diagnostics.

Apr 08, 2016 | Ford Cars & Trucks

1 Answer

How do I repl the vent solenoid on my 2007 trailblazer 6 cyl. I believe it is located on charcoal canister

Sorry you wasted your money on parts you didn't need ! There is a very specific diagnostic flow to testing this DTC - diagnostic trouble code ! An tools needed , scan tool , vacuum gauge ! the vent solenoid has nothing to do with this code .
Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views


Did you perform the Diagnostic System Check - Vehicle?
Go to Step 2
Go to Diagnostic System Check - Vehicle

  1. Disconnect the purge pipe from the evaporative emission (EVAP) canister purge solenoid valve.
  2. Install a hand held vacuum gage to the EVAP canister purge solenoid valve purge port.
  3. Disconnect the EVAP canister purge solenoid valve harness connector.
  4. Monitor vacuum on the vacuum gage.
  5. Start the engine and allow the engine to idle.
  6. Increase the idle to 1,200-1,500 RPM.
Does the vacuum gage indicate an increase in vacuum?
Go to Step 8
Go to Step 3


  1. Connect the EVAP canister purge solenoid valve harness connector.
  2. Monitor vacuum on the vacuum gage.
  3. Increase the idle to 1,200-1,500 RPM.
Does the vacuum gage indicate an increase in vacuum?
Go to Step 5
Go to Step 4

  1. Turn OFF the ignition.
  2. Remove and then install the fuel fill cap.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the Fuel Tank Pressure Sensor parameter with a scan tool.
Is the Fuel Tank Pressure Sensor parameter within the specified value?
-0.5 to +0.5 in H2O
Go to Diagnostic Aids
Go to Step 6


Test the control circuit of the EVAP canister purge solenoid valve for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs.
Did you find and correct the conditions?
Go to Step 9
Go to Step 8


Test for an intermittent and for a poor connection at the fuel tank pressure (FTP) sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.
Did you find and correct the condition?
Go to Step 9
Go to Step 7


Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement .
Did you complete the replacement?
Go to Step 9


Replace the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
Did you complete the replacement?
Go to Step 9


  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?
Go to Step 2
Go to Step 10


Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?
Go to Diagnostic Trouble Code (DTC) List - Vehicle
System OK

Feb 28, 2015 | 2007 Chevrolet Trailblazer

1 Answer

Diagnostic connector location

USA? what country?
RHD or LHD (right or left hand drive)?????
all usa cars, the 16pin DLC is less than 1meter from the steering wheel.
yours is behind the ash try(pull it)
some old honda's here, usa have dual ways to get scan codes.
the obd2 way , and obd1 way, RTM
read the FSM. or google for that.
I use , for fast answers, saving google searches and bad answers on forums...

fsm quote.
The 16-pin On Board Diagnostic version II (OBD-II) compliant Data Link Connector (DLC) is used to access the Diagnostic Trouble Codes (DTCs) using an OBD-II compliant Data Scan Tool (DST). It is an electrical connector with a gray housing located under the dash, either near the center console, on the passenger side of the vehicle or to the left of the driver side of the vehicle.
The two wire electrical connector with a blue housing next to the DLC is the Service Check Connector (SCS).

we (uSA have 2 DLCs. one is OBD2 and other is SCS.

id use a real scan tool. and not fool with the old winky blinky bs.
the scan tool you can check all live sensor data.
do that. and win.
1st goggle hit on SCS

Feb 18, 2014 | 1996 Honda Accord

1 Answer


DLC (Diagnostic Link Connector)

Dec 03, 2013 | 2006 Chevrolet Trailblazer

1 Answer

On-Board Diagnostic II (OBD II) Diagnostic Link Connector (DLC) Location in 1999 ford Ranger

the ecc diagnostic plug is what ford used b 4 going to the obd 2 system check with ur local ford dealer for checking codes

Jan 08, 2013 | Cars & Trucks

1 Answer

98 oldsmobile 88 royale code 12 and 41 what could be the problem


GM Bonneville/Eighty Eight/LeSabre 1986-1999
Reading Codes



See Figures 1 and 2
Listings of the trouble for the various engine control system covered in this manual are located in this section. Remember that a code only points to the faulty circuit, NOT necessarily to a faulty component. Loose, damaged or corroded connections may contribute to a fault code on a circuit when the sensor or component is operating properly. Be sure that the components are faulty before replacing them, especially the expensive ones.

0996b43f8021af66.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. Fig. 1: ALDL/DLC terminal identification for 1987-97 vehicles, except 1997 models with a 16-pin DLC
The Assembly Line Diagnostic Link (ALDL) or Data Link Connector (DLC) may be located under the dashboard, and is sometimes covered with a plastic cover labeled DIAGNOSTIC CONNECTOR.

  1. The diagnostic trouble codes can be read by grounding test terminal B . The terminal is most easily grounded by connecting it to terminal A (internal ECM ground). This is the terminal to the right of terminal B on the top row of the ALDL connector.
  2. Once the terminals have been connected, the ignition switch must be moved to the ON position with the engine not running.
  3. The Service Engine Soon or Check Engine light should be flashing. If it isn't, turn the ignition switch OFF and remove the jumper wire. Turn the ignition ON and confirm that the light is now on. If it is not, replace the bulb and try again. If the bulb still will not light, or if it does not flash with the test terminal grounded, the system should be diagnosed by an experienced driveability technician. If the light is OK, proceed as follows.
  4. The code(s) stored in memory may be read through counting the flashes of the dashboard warning lamp. The dash warning lamp should begin to flash Code 12. The code will display as one flash, a pause and two flashes. Code 12 is not a fault code. It is used as a system acknowledgment or handshake code; its presence indicates that the ECM can communicate as requested. Code 12 is used to begin every diagnostic sequence. Some vehicles also use Code 12 after all diagnostic codes have been sent.
  5. After Code 12 has been transmitted 3 times, the fault codes, if any, will each be transmitted 3 times. The codes are stored and transmitted in numeric order from lowest to highest.

The order of codes in the memory does not indicate the order of occurrence.
  1. If there are no codes stored, but a driveability or emissions problem is evident, the system should be diagnosed by an experienced driveability technician.
  2. If one or more codes are stored, record them. Refer to the applicable Diagnostic Code chart in this section.
  3. Switch the ignition OFF when finished with code retrieval or scan tool readings.

After making repairs, clear the trouble codes and operate the vehicle to see if it will reset, indicating further problems.

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Fig. Fig. 2: Engine diagnostic trouble codes - 1987-93 vehicles, and 1994 vehicles with a 12-pin DLC connector


See Figures 3 through 7

0996b43f8021af67.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. Fig. 3: DLC terminal identification for 1994 vehicles with a 16-pin DLC, as well as all 1995-99 models
On 1994-95 3.4L and 3.8L engines, and all 1996 models, an OBD-II compliant scan tool must be used to retrieve the trouble codes. Follow the scan tool manufacturer's instructions on how to connect the scan tool to the vehicle and how to retrieve the codes.

0996b43f8021af69.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. Fig. 4: Engine diagnostic trouble codes (1 of 4) - 1994 vehicles with a 16-pin DLC and all 1995-99 vehicles

0996b43f8021af6a.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. Fig. 5: Engine diagnostic trouble codes (2 of 4) - 1994 vehicles with a 16-pin DLC and all 1995-99 vehicles

0996b43f8021af6b.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. Fig. 6: Engine diagnostic trouble codes (3 of 4) - 1994 vehicles with a 16-pin DLC and all 1995-99 vehicles

0996b43f8021af6c.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. Fig. 7: Engine diagnostic trouble codes (4 of 4) - 1994 vehicles with a 16-pin DLC and all 1995-99 vehicles

May 04, 2012 | 1988 Oldsmobile Delta 88

3 Answers

How do I access DLC Port location in a 2002 Honda Odessey Minivan?

On 2002 Honda Truck Odyssey 3.5L MFI SOHC VTEC 6cyl the OBD Diagnostic Link Connector is located under the instrument panel in the driver's side. It is bolted to the kick panel and is gray in color on the 1998 and newer models.

Also refer to Haynes manual in the emissions and engine control system section .

Hope this helps; also keep in mind that your feedback is important and I'll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using Fixya, and have a nice day.

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Where is the diagnostic port located on my 2001 passat 5 sp. auto V6?

On the old Volkswagen Passat B5 (MY 1997-2001) the Data Link Connector (DLC) or diagnostic port is placed on the right side of the parking brake lever, under a small rectangle rubber cover. See pictures below:


On the new Volkswagen Passat B5 (after MY 2001) the Data Link Connector (DLC) or diagnostic port is placed on the panel above pedals. See pictures below:


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How do you program a 2006 Chevy Trailblazer EXT new power window master control switch?

{: ) After installing the new driver door/window switch, the programmer needs to have access to GM's TIS2Web service, and a diagnostic tool like the Tech2 or MDI to interface computer with the vehicle through the DLC terminals.

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All of a sudden my car has a miss and lack of power, a stumble when starting off.. The last time this happend it was a coil for cyl 3 & 8. how do I check this out ?


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