Monday, July 11, 2011

MKIII Jetta/Golf No Crank Diagnosis - 2.0 and VR6?

"When I turn the key nothing happens!!"

This "how to" assumes you have some basic tools, and safety gear. Safety glasses should be worn at all times when working with tools and automotive fluids. Always use a hydraulic jack and safety stands when lifting or getting under a vehicle. If you are unsure on where to safety lift your vehicle, refer to its owners guide. Batteries contain acid, and high current. Severe electrical and cheimcial burns may result from imroper battery testing, diagnosis, removal, or service. The writer of this how to assumes zero liability in how to use this guide, or any damages that may come from it to you, your property, or others and others property. If you are uncertain at any point, refer to a qualified automotive technician. Dispose of all waste materials based on your local laws.

The 2.0/VR6 starter is located on the transmission at the front of the engine. Open the hood, and look at the battery, look to the left of the battery in the engine bay. You will need a volt-ohm meter and test light to run these tests. All tests are done on the 12 V DC scale.

1 - Measure the voltage of the battery at the center of terminals.

Is it 12 volts or higher?

Yes, go to step 2

No - Charge and test the battery.

Batteries last about 5 years, how old is yours? To find your batteries age, this example.
Find a sticker on the battery, its a small sticker with a letter and a number like so;

A/7 A=January / 7 = 1997'

A fully charged battery should read 12.8 volts. A 50% charged battery will read 12.2 volts, and a dead battery reads 12 volts or below.

2 - Measure the voltage from clamp, to clamp on the battery

Is it EXACTLY the same voltage as step 1?

Yes, to step 3

No - Clean the battery terminals. Clean the terminals and make sure they are tight.

3 - Measure the voltage from the battery (+) terminal to the block of the engine. (must be bare unpainted metal)

Is it EXACTLY the same voltage as step 1?

Yes, to step 4.

No - Check or replace ground battery cable, and points on the block, and body where the cable is bolted down.

4 - Measure the voltage from the battery (-) terminal to the large terminal end on the starter.

Is it EXACTLY the same voltage as step 1?

Yes, to step 5.

No - Check or replace ground positive cable, and points on the starter where the cable is bolted down. Make sure to disconnect battery when servicing this cable, it is “hot” at all times. PIN 1 SHOWN BELOW

5 - Unplug the small single wire connector off the starter (the plug that goes into pin 3). Using a test light, ground one end of the test light to the engine block (must be bare unpainted metal), and put the probe of the test light into the plug youtook off of the starter. Ensure battery is hooked up for this test.

Have an assistant turn the engine to the CRANK or START position.

Does the test light - light up when the key is turned to the CRANK or START position?

Yes, to step 6

No - Automatic Transmission
Check to make sure car is in park.
Check Trans Range Switch, attempt to start car in Neutral
Make sure factory alarm is not active and beeping. (96’-99)
Check Anti-theft relay (Relay 53, position 21) (96’-99)
Ensure Factory radio is installed, or bypassed (96’-99)
Check Ignition switch for failure.
Check Park Relay in Fuse Box

No - Manual Transmission
Check to make sure clutch depressed to floor. (96’-99)
Check Ignition switch for failure.
Make sure factory alarm is not active and beeping. (96’-99)
Check relay (Relay 53, position 21) (96’-99) (upper right of fuse box)
Ensure Factory radio is installed, or bypassed (96’-99)

Step 6 - Ensure battery is hooked up for this test.

Ensure keys are out of the ignition and that the car is in neutral or park! If the car is in gear, any gear, or in drive, it will RUN YOU OVER! Make sure parking brake is set!

Using a fused 30amp jumper wire jump power from the small pin on the back terminal of the starter (where you tested it in step 5), and jump power to the large terminal on the starter.
(JUMP PIN 1 to PIN 3)

(drawing not by me..)

The starter should crank the engine. There will be a good spark as current is sent to the starter.

Did the starter crank the engine?

Yes - Your car does not have a cranking issue; it has a no-start issue, check for fuel, spark, timing, and compression.

Yes, but it cranks slowly, or made a funny sound. - Check battery voltage again or engine mechanical starter or engine defect.

No - Replace starter.


Can I bypass the alarm?


1 - find alarm module (near headlight switch), drop relay panel down.

2 -

3 - Jump the two wires (on the harness side) shown.



What is it? - Its your factory alarm in your MKIII Golf or Jetta. All US cars came with a central locking system and a factory perimeter alarm.

And for the the most part, it works fine. Arming itself when you lock the car with a key fob or key in the door. Un-arming itself when you unlock a door. The factory central lock system uses a vacuum pump system (in the trunk, or rear of the car..) and makes a "moan" when its running. On Jetta/Vento cars the lock pump is on the drivers side. On Golf cars the pump is located on the passenger side.

In general the system works like this:

When the drivers door is "locked" all doors will also lock. Red LED on drivers door will flash. Car will "arm" with all doors, hood, and trunk closed (and latched down).

One turn from the drivers door to unlock the car opens the drivers door, and cancels the alarm. Two turns to unlock opens all doors.

If a trunk, hood, or door is opened the alarm will go off, the lights (on later cars) will flash, the alarm will go off, and the the starter will be disabled.

The only way to disarm the system is to press unlock on the factory remote, or unlock the drivers door with a key. Putting the key in the ignition will not cancel an alarm.

Inserting a key into the drivers (or passenger door) lock cylinder and turning and *holding* the key in the lock position will arm the system and then close all windows and the then sunroof. (note, power windows and/or electric sunroof only).

Unlocking the car the same way will - one unlock opens drivers door (mechanically), and turns off alarm. Two turns will unlock ALL doors - and if its "held" in the unlock position - will open all power windows (note, the sunroof will not open)

The factory system only disables the starter. If the car cranks - the alarm is not at fault. The US MKIII system does not have a "Immobilizer" like the MKIV models do. There is NO "chip" in the key.

But problems arise and things go wrong. The alarm "goes" off at all hours of the night, or worse it prevents the car from starting! But lets look at some key facts..

Note: This page does *not* cover the Cabrio immobilizer system found on MK3.5 (1999.5-2002) cars.

The MKIII model line, as said earlier were all equipped with factory door central lock systems. However, there are a few odd ball cars out there, and of course, alarm systems changed from year to year... but here goes:

1993-1995 - Central Lock System w/Alarm. System as drivers and passenger door lock cylinders. To lock all doors in the car, the drivers door pin is the "central lock switch" and all other door pins follow suit. Alarm module is Silver. These cars also have a locking fuel door as part of the central lock system. The car must be "unlocked" to gain access to the fuel filler. This added feature may be added to later cars by adding and tapping into the central lock vaccum system and getting an older style fuel door lock.

1996-1997 - Same as above, but added a central lock switch button in center console. Also added flashing lights to arm/disarm/alarm (parking lights). Alarm module is Black.

1998-1999.5 - Same as above, but added *factory keyless*, removed passenger side door lock cylinder. Remotes are Banjo shaped, and Alarm module is White. - Deleted passenger side door lock cylinder. If the car is "disarmed" or "unlocked" AND it does NOT see a door, trunk, or hood open in 30 seconds, it will re-arm itself.

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