Resetting Check Engine Light

tommy37

Veteran Member
Joined
Nov 19, 2000
Location
Rockville, Maryland USA
Anyone know how to reset the CEL on my 99.5 Jetta TDI? How about my 1996 Ford Escort 1.9L (no, really--it's on in both cars).

On my old Shadow, it was something like this--

You put the key in
You take the key out
You put the key in
And you turn it all about
You do the Hokey-Pokey
And you take the key back out in 15 seconds or so
Then the light should go out.
 

BioDiesel

Veteran Member
Joined
Oct 29, 2001
Location
CT
TDI
'98 Jetta
Someone else posted to this forum that after 30 sucessfull starts, the code would clear itself.
That was not my experience however, on my '98 A3 Jetta. It took the VAG-COM trial-ware software to
clear the CEL.
 

weedeater

Top Post Dawg
Joined
Mar 17, 2001
Location
Reston, VA
TDI
Jetta, 2001, Baltic Green
Depends on the failure.

Some (sensor value bad) let the light clear after 3 restarts, usually the intermittent faults.

Others (sensor broke) won't clear until you fix it.
 

weedeater

Top Post Dawg
Joined
Mar 17, 2001
Location
Reston, VA
TDI
Jetta, 2001, Baltic Green
If the GP you put in is not of the same type (manufacturer) as the others, the mismatch can keep causing the failure eventhough it is a new plug. Did you measure the ohms on the new plug and is it with in 1 ohm of the others?
 

BioDiesel

Veteran Member
Joined
Oct 29, 2001
Location
CT
TDI
'98 Jetta
I should have provided more info.
I had the 10550 ? code for ' Glow Plug Failure'
After checking their resistance, one of them indeed read was above the maximum ohm value.
I put in a new one and waited for 30 restarts. The CEL never went out.
It went out when I cleared it with the VAG-COM.

I'm just guessing, but it seems some failures
are stored in non-volatile ( permanent ) memory.
Since it's all under computer control, it
may require X number of non- fault readings / conditions, or may require it to be 'manually' cleared. All of this could change between ECM modules by vendor or software revision.
Or as you point out, less serious failures
may be allowed to clear themselves.

Jim
 
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