Output Check Diagnosis
Note
The following components (in the sequence as listed) can be checked using this procedure.
1. Differential pressure regulator (N 73)
2. Carbon canister solenoid valve I (N 80)
3. Idle stabilizer valve (N 71)
4. Cold-start valve (N 17)
Requirements
^ fuses 15 and 21 OK
^ idle switch OK
^ ignition switched OFF
^ connect VAG 1551 diagnostic tester using adaptor cable VAG 1551/1 as follows:
^ black wire to black diagnostic connector 1
^ white wire to white diagnostic connector 2
^ blue wire NOT used
Following display appears:
VAG SELF-DIAGNOSIS HELP
1 - Rapid data transmission*
2 - Flash code output*
*appears alternately
^ switch multimeter US 1119 (or equivalent) to Amps range
^ connect multimeter to differential pressure regulator using VAG 1315A/1 test adaptor
^ switch ON ignition
^ press button 1 of VAG 1551 diagnostic tester
^ operating mode "rapid data transmission" is selected
Following display appears:
Rapid data transmission HELP
Input address word XX
^ press "0" and "1" buttons to select function 01:
engine electronics
Following display appears:
Rapid data transmission Q
01 - engine electronics
^ acknowledge input by pressing "Q" button The control unit identification appears on the display, for example:
893907404 F motor ->
Press -> button
Following display appears:
Control unit does not respond! HELP
^ press HELP button
^ list of possible fault causes will print
^ press -> button
^ following display appears
Rapid data transmission HELP
Select function XX
^ press "0" and "3" buttons to select function 03:
"output check diagnosis"
Following display appears:
Rapid data transmission Q
03 - output check diagnosis
^ acknowledge input by pressing "Q" button Following display appears:
Output check diagnosis ->
Differential pressure regulator (N 73)
^ observe control current on multimeter
^ control current must fluctuate from 0 to 100 mA ->
If NO
^ check wiring using wiring diagram
^ check differential pressure regulator resistance
^ 15 to 25 Ohms, see section D2-90 test step 6
If wiring and resistance measurement OK
^ replace CIS-E Motronic control unit (J 204)
^ press -> button Following display appears:
Output check diagnosis ->
Solenoid 1 for carbon canister (N 80)
^ solenoid I must click
If valve does not click
^ check control as follows:
^ remove harness connector from solenoid valve I
^ connect LED tester US 1115 (VAG 1527B) to harness connector using VW 1594 adaptor kit
^ LED must flash
If LED flashes
^ replace solenoid valve I
If LED does NOT flash
^ check wiring, see section D2-90 test step 11
If wiring OK
^ replace CIS-E Motronic control unit (J 204)
^ press -> button
Following display appears:
Output check diagnosis ->
Idle stabilizer valve (N 71)
^ idle stabilizer valve must click
If NO
^ check control as follows
^ switch OFF ignition
^ disconnect idle stabilizer valve harness connector
^ connect valve to harness connector using adaptor wires VW 1594 /1, /2 and /19
^ connect LED tester to adaptor wire VW 1594/19 using adaptor VW 1594/15
^ repeat output check diagnosis from the beginning
When display: "idle stabilizer valve (N 71)" has been obtained
^ LED must flash
If LED flashes
^ replace idle stabilizer valve
If LED does NOT flash
^ switch multimeter US 1119 (or equivalent) to resistance range
^ measure idle stabilizer valve resistance
^ must be 4 to 12 ohms
^ check wiring, see section D2-90 test step 3
If wiring OK
^ replace CIS-E Motronic control unit (J 204)
^ press -> button
Following display appears:
Output check diagnosis ->
Cold-start valve (N 17)
^ open throttle slightly
^ cold-start valve must click
Note
The valve is activated only ten times to avoid "flooding" the engine. To perform another test, the output check diagnosis must be repeated from the beginning.
If the valve does not click, check control as follows:
^ disconnect cold-start valve harness connector
^ connect LED tester to harness connector using adaptor kit VW 1594
^ perform output check diagnosis again from the beginning When display "cold-start valve (N 17)" is obtained
^ open throttle valve slightly
^ LED must flash ten times
If LED flashes
^ replace cold-start valve
If LED does NOT flash
^ check wiring, see section D2-90 test step 10
If wiring OK
^ replace CIS-E Motronic control unit (J 204)