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Model specific boards => Golf mk4 => Topic started by: MrJonSavage on 30 November 2012, 23:29
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Been testing my Pre & Post Cat sensors via VCDS & good old fashioned multimeter & need bit help deciding what results mean...
Used the Volkswagen Workshop Manuals online;
pre cat : http://volkswagen.workshop-manuals.com/golf-mk4/index.php?id=4180
post cat : http://volkswagen.workshop-manuals.com/golf-mk4/index.php?id=4181
For the pre-cat I get the following results;
Via VCDS:
display zone 1: 80 Ohms (spec: 6.4-47.5 Ohm) [very high obviously]
display zone 2: Htg.S1.ON (NOT alternating to 'OFF')
Via multimeter:
Continuity between pins 1+2: GOOD
Voltage between pins 1+2 as engine idles: NO VOLTAGE & NO alternating between Htg.S1.ON/OFF (as above)
Don't have a test box 'VAG 1598/22' (2k price to buy online?!)
For the post-cat I get the following results;
Via VCDS:
Display Zone 3: 15 Ohms (spec: 6.4-47.5 Ohms): GOOD
Display Zone 4: Htg.S2.ON (NOT alternating to 'OFF')
Via multimeter:
Continuity between pins 1+2: GOOD
Voltage between pins 1+2 as engine idles: NO VOLTAGE & NO alternating between Htg.S2.ON/OFF (as above)
SO, this would seems to indicate that the Pre-Cat has too high a resistance, continuity, but no voltage when engine idling. For the post cat, within tolarance resistance, continuity but no voltage when engine idling.
Now, went on to do the VCDS Engine Measured Blocks tests:
Block 002: No MAF sensor (1.6 SE DOHC engine, MAP sensor but can't find where this is located to test on VCDS [any ideas?])
Block 030: Oxygen Sensor Regulator: Field1: 1 1 1/0 when rev's, Field2: 1 1 0 (NO fluctuation) : OK?
Block 032: Oxygen Sensor Learned Values: F1: -10.0% (other test=-3.0%), F2: 0.0% : Running rich at the pre-sensor?
Block 033: Pre-Cat Oxygen Sensor Control: F1 -2.0-0.0% fluctuation: OK?
Now via Basic Settings in VCDS Engine:
Block 036: Post-Cat Oxygen Sensor Control: F1: 0.756V (0-1V = ok), F2: B1-S2 OK: = Post Cat good?
Block 034: Ageing of Pre Cat Oxygen Sensor: F3 (0.81/0.88 [2nd test] (Must be > 0.8 [new sensor = 1.99]): So Pre Cat JUST on line of being ok?
Block046: Lambda: F3: 94.5% [2nd test: 87%], F4: CAT B1 OK : Catalytic Convertor OK?
SO: What's your ideas from this & please no glib 'it's f*cked mate' :angry:, put down why you think what you do even if it's obvious to you. Anything else to test here for the Pre/Post/Cat itself?!