Also it says to bridge e1 and te1, whilst the meter is connected(i think) to vf1 and e1 ( I get 0.04volts between vf1 and e1)I'm either doing it wrong or my o2 sensor is duff.
..Any other ways of testing if it's done?
MkII O2 Sensor Diagnosis
From: Dave Inskeep
([email protected])Date: Thu, 31 Jul 1997 23:43:42
-0400Subject: Re: MR2 O2 Sensor Diagnosis
Here's the procedure from the 91 Toyota manual.
I'm adapting a flowchartthat had some redundant steps, so I hope this doesn't get too confusing.
Myown comments are in
[]. If anyone else on the list has the Toyota manual,please check this to see if I misread something.
A1.
Connect the positive probe of an analog (needle type) voltmeter toterminal VF1 of the check connector, and the negative probe to terminal E1.
A2.
Warm up O2 sensor with the engine at 2500 rpm for ~120 seconds.A3.
Connect terminals E1 and TE1 of the check connector. Maintain enginespeed at 2500 rpm.
A4.
Check the number of times the needle fluctuates in 10 seconds: a. If 8 times or more, normal. b. If less than 8 times, verify that O2 sensor and engine have been warmfor at least 120 seconds and the engine speed is held at 2500 rpm.
Repeatstep A4.
c. If zero times, goto step B1. d. If greater than zero or less than 8 times, go to step A5. e. If zero after replacing the O2 sensor once already, replace the ECU.A5.
Disconnect terminals TE1 and E1 of the check connector, maintain 2500 rpm.A6.
Measure the voltage between terminals VF1 and E1: a. More than 0 volts, replace the O2 sensor & repeat from A1. b. If 0 volts, goto to step A7.A7.
Check the diagnostic codes: a. Normal code nos. 21, 25, and 26: goto step A8. b. Malfunction codes - any other than 21, 25, 26, repair the code.A8.
Disconnect the PCV hose.A9.
Measure the voltage between terminals VF1 and E1. a. 0 volts, replace the O2 sensor & repeat from A1. b. More than 0 volts, repair (over rich). [I'm not sure what they mean torepair
- this is straight from the book. Perhaps they mean just repairwhatever is causing the over-rich condition?]
B1.
Check the diagnostic codes: a. Normal code nos. 21, 25, and 26: goto step B2. b. Malfunction codes - any other than 21, 25, 26, repair the code.B2.
Disconnect terminals TE1 and E1 of the check connector, maintain 2500 rpm.B3.
Measure the voltage between terminals VF1 and E1: a. If 0 volts, goto to step A8. b. If 5 volts, proceed to step B4. c. [If in between 0 and 5 volts, not sure what to do. I guess it's aneither/or thing, I haven't done this part myself.
]B4.
Disconnect the water temp sensor connector and connect resistor with aresistance of 4-8 kOhms or another coded
[?] water temp sensor.B5.
Connect terminals TE1 and E1 of the check connector.B6.
Warm up the O2 sensor with the engine at 2500 rpm for approx 120seconds, maintain 2500 rpm.
B7.
Measure voltage between terminals VF1 and E1. a. If 0 volts, replace the O2 sensor & repeat from A1. b. If 5 volts, repair (over lean).Good Luck,
Dave Inskeep
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