Engine light came on. Ran Diagnostic computer from checker Auto. Got code "p064 cylinder 4 glow plug circuit" What does that mean, a new glow plug?

DTC P0671: Cylinder #1 Glow Plug Control Circuit
DTC P0672: Cylinder #2 Glow Plug Control Circuit
DTC P0673: Cylinder #3 Glow Plug Control Circuit
DTC P0674: Cylinder #4 Glow Plug Control Circuit
DTC P0675: Cylinder #5 Glow Plug Control Circuit
DTC P0676: Cylinder #6 Glow Plug Control Circuit
DTC P0677: Cylinder #7 Glow Plug Control Circuit
DTC P0678: Cylinder #8 Glow Plug Control Circuit

Circuit/System Description
The glow plug controller has the ability to perform internal checks, an open or a short to ground on each of the glow plug circuits. If the glow plug controller senses a problem in a glow plug circuit, the glow plug on the affected cylinder will be disabled and the glow plug controller will send an error message to the engine control module (ECM). If this condition exists, the DTC will set.
Conditions for Setting the DTC
The glow plug controller detects that the glow plug control circuit is open, shorted to ground, or has more than 1 ohm of resistance.

Circuit/System Verification
Verify that DTC P064C is not set.
If DTC P064C is set, refer to DTC P064C.
Ignition ON, engine OFF, observe the scan tool Glow Plug 1-Glow Plug 8 parameters. All 8 Glow Plug parameters should closely match each other.
Refer to Testing for Intermittent Conditions and Poor Connections if you cannot duplicate the conditions.
Engine running, observe the DTC information with a scan tool. DTCs P0671-P0678 should not set.
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 data.

DTC C0035 Left Front Wheel Speed Sensor Circuit
DTC C0201 Antilock Brake System (ABS) Enable Relay Contact Circuit
The system relay, located within the electronic brake control module (EBCM), supplies battery voltage to all of the valve solenoids and to the ABS pump motor. When the relay contacts close, the EBCM monitors the voltage supplied to the valve solenoids and compares this voltage to monitored ignition voltage.

Error Code: P0404
Fault Location:
Exhaust Gas Recirculation (EGR) System - Range/Performance Problem
Causes:
-Hose leak/blockage.
-Wiring harness.
-Exhaust gas recirculation (EGR) valve/solenoid.
Error Code: P0473
Discription:
Exhaust Gas Pressure Sensor - High Input
Causes:
- Wiring short to positive.
- Exhaust gas pressure sensor (G450).
- Engine control module (ECM).
Error Code: P0674
Description:
Glow Plug Cylinder 4 Circuit - Circuit Malfunction
Causes:
-No Pre-Glow Period.
-Poor Cold Starting.
-Glow Plug Wiring faulty.
-Poor connection.
-Relay.
-Glow plug control module.
-Glow Plug faulty.
-Engine control module (ECM).
Solutions:
Check Glow Plug Wiring.
Check Glow Plug.
Error Code: P0675
Description:
Glow Plug Cylinder 5 Circuit - Circuit Malfunction
Causes:
-No Pre-Glow Period.
-Poor Cold Starting.
-Glow Plug Wiring faulty.
-Poor connection.
-Relay.
-Glow plug control module.
-Glow Plug faulty.
-Engine control module (ECM).
Solutions:
-Check Glow Plug Wiring.
-Check Glow Plug.

HI,
http://engine-codes.com/p0671_gmc.html

It's a Glow Plug.

Possible causes- Cylinder #1 glow plug circuit is open or shorted
- Faulty cylinder #1 glow plug
- Faulty glow plug module Help with thisSymptoms- Engine Light ON (or Service Engine Soon Warning Light)
- Lack/Loss of Power
- The engine may be harder to start
- Engine hesitation

Read more: http://engine-codes.com/p0671_gmc.html#ixzz28UT1VO75

Hi there:

DTC P0627 CHRYSLER - Fuel Pump Relay Control Circuit
ECM (Engine Control Module) detected an open or short in the fuel pump relay circuit
Possible causes
- Fuel pump circuit open or short
- Fuel pump circuit poor electrical connection
- Faulty fuel pump relay
- Faulty fuel pump control module (if applicable)


DTC P0680 - Cylinder 10 Glow Plug Circ, and,

DTC P0681 - Cylinder 11 Glow Plug Circ
The Engine Control Module (ECM) has detected a fault in the cylinder #10 or #11 glow plug circuit.


Possible causes
- Cylinder #10, or #11 glow plug circuit is open or shorted
- Faulty cylinder #10 or #11 glow plug
- Faulty glow plug module Help with this


DTC P0688 CHRYSLER - Auto Shutdown Relay Control Circuit Low

The Front Control Module (FCM) has detected the supply voltage below an acceptable value.

Possible causes
- ASD relay circuit is open or shorted
- Failed Auto Shutdown relay
- Failed ECM


Check all the ECM fuses, if the fuses are OK try replacing the ASD relay.

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, have a nice day.

OBD Code P0673refers to
The Engine Control Module (ECM) has detected a fault in the cylinder #3 glow plug circuit SymptomsPossible sumptoms of OBD code P0673
- Engine Light ON (or Service Engine Soon Warning Light) - Lack/Loss of Power - The engine may be harder to start - Engine hesitation CausesPossible causes of OBD code P0673
- Cylinder #3 glow plug circuit is open or shorted - Faulty cylinder #3 glow plug - Faulty glow plug module

The code P0674 tells you that something in the glow plug circuit is faulty causing the glow plug on cylinder #4 to fail to heat up. The entire circuit must be checked to locate the fault.

Symptoms With just one glow plug failure other than the check engine light coming on, the symptoms will be minimal since the engine will normally start with one bad plug, under freezing conditions you would be more likely to experience hard starting.

Potential Causes The causes for this DTC may include: Faulty cylinder #4 glow plug Open or shorted glow plug circuit Damaged wiring connector Faulty glow plug control module Diagnostic Steps & Possible Solutions You will need a digital volt ohm meter (DVOM) for the complete test.
Continue through the tests until the problem is confirmed. You will also need a basic OBD code scanner to reset the computer and erase the code. Check the cylinder #4 glow plug by disconnecting the wire connector on the plug. Place the DVOM on ohms and place the red lead on the glow plug terminal and the black lead on a good ground. The range is .5 to 2.0 ohms, if it is out of range replace the glow plug.

If you have replaced the glow plugs....replace glow plug harness. If code reappears, replace glow plug controller.

FYI: VW numbers the glow plugs backwards. IE: #1 cylinder next to the timing belt cover is number #4 glow plug...so your #2 is actually #3 on the engine.

HI. This is an indication of a failing glow plug. It will be necessary to test each plug to isolate the issue, or run a diagnostic scan on the CPU. During the scan, you should be issued a code that will isolate the actual glow plug that is malfunctioning. If you insist on testing each plug, use my procedure below to assist. You can find the resistance specs in your operators manual.


A test light can be used to determine if the glow plugs are working.


1. With the test-light grounded, insert the test light probe into a glow-plug wire to check for continuity.

2. If the light comes on, check the other cylinders in the same manner. If the test light failed to light, check for continuity at the glow-plug relay.

3. If no power is present, check the control circuit of the glow plug relay.

4. If the control circuit is working, the relay may be defective (FYI, manufacturers may have the system fused and fusible links may be located throughout the system).

5. If the glow-plug circuit is working, the glow plugs themselves may be defective.

Checking glow-plug resistance:(Remove the plug for this test)

1. With an ohmmeter, connect one lead to the terminal and the other lead to the body.

2. Read the resistance and compare to specifications.

3. A visual inspection may also be necessary to check for excessive carbon buildup and physical damage to the tip.

4. A glow plug that has excessive carbon deposits on its tip can give the correct ohmmeter reading but still not work. Clean the tip with carbon cleaner.(DO NOT USE A BRUSH TIP CLEANER)

It means the Engine Control Computer has picked up a fault of some kind. Many service providers will give you a free 'diagnostic' - they'll plug in a code reader and the code reader will tell you which fault occured. Most Checker auto parts places will read the engine codes free. If you disconnect the battery for two minutes, then reconnect, and the warning goes away, it was an intermittent fault - not to worry.

Gene, in AZ

You probably need to replace the glow plug harness. The contacts in the boots that connect to the glow plugs get corroded and throw off the resistance of the circuit. The controller in the VW measures whether your glow plugs are good or not by testing the resistance in the circuit. Test all the glow plugs like DickyIV1 stated and if they are all good try cleaning out the crud on the contacts in the glow plug harness. You will then either need to clear the error code or wait several trips for it to clear itself. If it never clears itself or if it comes back on after you clear it then the glow plug harness is too much of a mess. This is really common on the TDIs (mine needs to be changed but i have been putting it off and ignoring the mil light). When I first tried cleaning the harness on my car it didn't give me a problem for another year and a half. But I knew I'd eventually be changing it.
The other thing to keep in mind is that you should change out glow plugs as a set. It causes less problems in the long run since if one failed you will probably find other will soon fail and it keeps all the resistance close to the same value.