does clearing codes empty the 'drive cycle'?

I have a 2003 golf TDI and it has always thrown the code for the 3rd cyl glow plug. I clear the code and it sails thru Oregon DEQ just fine. This last time I was told the 'drive cycle' data was empty and all readings were either 'unsupported' or 'not ready'.
Any advice or comments?

The fault is probably intermittent so when it gets cleared it just takes a while to come back. I think it gets written to some sort of memory like when you use a flash drive for a pc, they're then stored til you clear them and I would guess that's what's meant by drive cycle. This is the first time I've heard the term "drive cycle" so can only hazard a guess.

jaxworks said:

I have a 2003 golf TDI and it has always thrown the code for the 3rd cyl glow plug. I clear the code and it sails thru Oregon DEQ just fine. This last time I was told the 'drive cycle' data was empty and all readings were either 'unsupported' or 'not ready'.
Any advice or comments?

Click to expand...

He almost certainly means the readiness statuses. Once you clear out codes, the emissions status are also reset. It takes driving around for a bit to get the various checks to recalibrate and get to an OK or Ready state.

You can't clear out and go immediately to the testing station.

In VCDS, you can verify that everything's good to go under Module 1 - Readiness.

Do a search for "readiness codes" if you need to find out more about this.

reset rediness

Not the easiest thing to do but here it is

Volkswagen > A4 Platform > 1999 - 2005
1.9 Liter 4-Cyl. 2V TDI and TDI PD Generic Scan Tool, Engine Code(s): ALH, BEW
ST - Generic Scan Tool
Readiness code, generating
The respective fuses of Diesel-Direct fuel injection system must be OK:
=> Electrical Wiring Diagrams, Troubleshooting & Component Locations
Battery voltage must be at least 11.5 volts.
All electrical consumers such as, lights and rear window defroster must be switched off.
If vehicle is equipped with an A/C system, it must be switched off.
Ground (GND) connections between engine and chassis must be OK.
There must not be any DTCs stored in DTC memory => page VW-A4-FU14-ST-002-05ST-22, Diagnostic mode 3: Check DTC memory.
Vehicles with engine code ALH
Coolant temperature must be at least 80 ° C => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.
Vehicles with engine code BEW
Coolant temperature must not be above the maximum of 25 ° C => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.
Work sequence:
Vehicles with engine code ALH => page VW-A4-FU14-ST-003-03ST-51,
Vehicles with engine code BEW => page VW-A4-FU14-ST-003-03ST-54.
Work sequence (Vehicles with engine code ALH )
Connect diagnostic tester => page VW-A4-FU14-ST-001-03ST-7.
Switch ignition on.
Wait 5 seconds.
Let engine run at idle.
Wait 45 seconds.
Perform a road test.
The following operating conditions must be met during this road test:
With accelerator pedal depressed completely, accelerate vehicle in 3rd gear or in driving mode "3" from 50 km/h to 120 km/h.
Drive for 2 minutes in 4th gear or in driving mode "D" on a level driving surface at a constant vehicle speed with an engine speed of 1700 to 1900 RPM.
Observe the safety precautions that apply to road tests => page VW-A4-FU14-23-001-1223-46.
Note:
Vehicle speed => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 13, Vehicle speed.
Engine speed => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 12, engine rotations per minute (RPM).
Park vehicle and switch off ignition.
Wait 15 seconds.
Switch ignition on.
Wait 5 seconds.
Let engine run at idle.
Wait 45 seconds.
Perform a road test again.
The following operating conditions must be met during this road test:
With accelerator pedal depressed completely, accelerate vehicle in 3rd gear or in driving mode "3" from 50 km/h to 120 km/h.
Drive for 2 minutes in 4th gear or in driving mode "D" on a level driving surface at a constant vehicle speed with an engine speed of 1700 to 1900 RPM.
Observe the safety precautions that apply to road tests => page VW-A4-FU14-23-001-1223-46.
Park vehicle and let engine run at idle for 3 minutes.
Accelerator pedal must not be operated during this time.
Read readiness code => page VW-A4-FU14-ST-003-02ST-48.
If a 1 is displayed instead of a 0 in the 8-digit number block:
Repeat complete work procedure => page VW-A4-FU14-ST-003-03ST-51
Work sequence (vehicles with engine code BEW)
Connect diagnostic tester => page VW-A4-FU14-ST-001-03ST-7.
Switch ignition on.
Wait 5 seconds.
Let engine run at idle.
Wait 45 seconds.
Perform a road test.
The following operating conditions must be met during this road test:
Bring coolant temperature to at least 85 ° C via road test => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.
Drive for 20 seconds in 4th gear or in driving mode "D" on a level driving surface at a constant vehicle speed with an engine speed of 1700 to 1900 RPM.
Accelerate vehicle to 100 km/h.
Drive for 2 minutes in 5th gear or in driving mode "D" on a level driving surface at a constant vehicle speed of 100 km/h (no deceleration).
Then from 100 km/h, decelerate (do not brake) in 5th gear or in driving mode "D" to 900 RPM.
Observe the safety precautions that apply to road tests => page VW-A4-FU14-23-001-1223-46.
Note:
Vehicle speed => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 13, Vehicle speed.
Engine speed => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 12, engine rotations per minute (RPM).
Park vehicle and let engine run at idle for 3 minutes.
Accelerator pedal must not be operated during this time.
Switch ignition off.
Switch ignition on again.
Let engine cool off:
Coolant temperature must not be above the maximum of 25 ° C => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.
Let engine run at idle.
Wait 45 seconds.
Perform a road test again.
The following operating conditions must be met during this road test:
Bring coolant temperature to at least 85 ° C via road test => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 5, Coolant temperature.
Drive for 20 seconds in 4th gear or in driving mode "D" on a level driving surface at a constant vehicle speed with an engine speed of 1700 to 1900 RPM.
Accelerate vehicle to 100 km/h.
Drive for 2 minutes in 5th gear or in driving mode "D" on a level driving surface at a constant vehicle speed of 100 km/h (no deceleration).
Then from 100 km/h, decelerate (do not brake) in 5th gear or in driving mode "D" to 900 RPM.
Observe the safety precautions that apply to road tests => page VW-A4-FU14-23-001-1223-46.
Note:
Vehicle speed => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 13, Vehicle speed.
Engine speed => page VW-A4-FU14-ST-002-03ST-16, Diagnostic mode 1: Check measured values; PID 12, engine rotations per minute (RPM).
Park vehicle and let engine run at idle for 3 minutes.
Accelerator pedal must not be operated during this time.
Read readiness code => page VW-A4-FU14-ST-003-02ST-48.
If a 1 is displayed instead of a 0 in the 8-digit number block:
Repeat complete work procedure => page VW-A4-FU14-ST-003-03ST-51

jaxworks said:

I have a 2003 golf TDI and it has always thrown the code for the 3rd cyl glow plug. I clear the code and it sails thru Oregon DEQ just fine. This last time I was told the 'drive cycle' data was empty and all readings were either 'unsupported' or 'not ready'.
Any advice or comments?

Click to expand...

What does Oregon require to pass??? You should be able to look it up on their website.

Apparently, readiness status is not one of the checks. Otherwise, you would not pass and be told to drive the car more to complete a driving cycle and then come back and have readiness rechecked. In some states that check readiness, you can have one maybe two of the 8 readiness bits "not ready" and still pass as long as you don't have a CEL. You don't have to worry about readiness bits that are not supported.

Sometimes, you can achieve an OK status for all the readiness bits after clearing a fault code before the CEL reappears (especially fault codes that take a longer time to reach a threshold value before triggering the CEL) and successfully pass emissions even though the fault code and CEL will eventually reappear. For example, in my 2000 Passat I would get several catalytic converter fault codes and several not ready status bits. I would clear the codes, drive for a few days until the readiness bits were OK and then take it for inspection. The CC codes would eventually come back after around 500 - 1000 more miles of driving.

Does anybody know a trustworthy TDI shop (not OWOSCO!) in the Whitby/Oshawa area? I have a CEL on and need to pass a drive clean ASAP on my 2004 TDI Jetta wagon.

Drive cycle means exactly that. It is from when you start the car, drive the car and shut it off with all the conditions in post 4 met.

What a successful drive cycle does is resets DTC's(codes) that are self clearing and for DTC's that are not self resettable but have been cleared sets reediness providing there are no active DTC's.

hi...
Personally I would drive the car enough to get it well warmed up, then turn it off, remove the key and close the door to complete the power off cycle. Then restarting the car will initiate a new cycle. After you do this 6 times it should be at what ever end state its going to achieve under current conditions.
PREVENTATIVE VEHICLE MAINTENANCE

amit65 said:

hi...


Personally I would drive the car enough to get it well warmed up, then turn it off, remove the key and close the door to complete the power off cycle. Then restarting the car will initiate a new cycle. After you do this 6 times it should be at what ever end state its going to achieve under current conditions.

Click to expand...

Unless things are different by you the motor has to cool down below a certain temperature before a new drive cycle can occur.

search my username in these forums using the keyword"readiness" and you will find a lot of info about how readiness works in a tdi ecu.