ECU Diagnostics for a Toyota
Discussion
I need a doctor for a Toyota Corolla 1.6 16v that has failed MOT with erratic (and generally high) CO emmission. Lambda and temperature sensors tested OK with a voltmeter, so a more sophisticated diagnosis is required.
A mate with an MR2 recently paid £300 to be told he needed a new cat and so I want to avoid that place.
Can anyone recommend a garage in the Bristol area equipped for diagnostics of a Toyota?
Cheers
Rat
A mate with an MR2 recently paid £300 to be told he needed a new cat and so I want to avoid that place.
Can anyone recommend a garage in the Bristol area equipped for diagnostics of a Toyota?
Cheers
Rat
Have you got a diagnostic connector in the engine bay? Ony my similar aged MR2 you can read the error codes with a paperclip - google for "Toyota TE1" or check
[url]www.club4ag.com/faq%20and%20tech_pages/ECU%20Diagnostic%20Codes.htm[/url]
The codes can sometimes be misleading though, I'd look for coroboration before condeming anything expensive
[url]www.club4ag.com/faq%20and%20tech_pages/ECU%20Diagnostic%20Codes.htm[/url]
The codes can sometimes be misleading though, I'd look for coroboration before condeming anything expensive
Thanks Aldi
You can read the error codes with a procedure that involves bridging two terminals on the test socket and then counting the flashes of the engine warning light.
I did get a code 21 that corresponds to 'exhaust emission circuit'. Not very helpful. Tested all sensors in that circuit with voltmeter and they were OK. Reset the error code and went for a few test drives and the code didn't reappear, but CO emission still too high.
Have now done all 'helpful' things like replaced oil, fuel/air/oil filters, run some injector cleaner through, tested all the rest of the sensors that can be tested with basic voltmeter and the vacuum lines. But I didn't find any obvious problems and the car has done <5000 miles since I last did most of these a year ago, so I fear I have just thrown good money after bad. Will probably bite the bullet and book into a dealership for emission test and diagnosis next prior to trying full MOT retest. Bit of a pain as nearest is 20 miles away from me and now the old MOT has expired, as well as being potentially expensive for a car that's worth less than the likely bill.
You can read the error codes with a procedure that involves bridging two terminals on the test socket and then counting the flashes of the engine warning light.
I did get a code 21 that corresponds to 'exhaust emission circuit'. Not very helpful. Tested all sensors in that circuit with voltmeter and they were OK. Reset the error code and went for a few test drives and the code didn't reappear, but CO emission still too high.
Have now done all 'helpful' things like replaced oil, fuel/air/oil filters, run some injector cleaner through, tested all the rest of the sensors that can be tested with basic voltmeter and the vacuum lines. But I didn't find any obvious problems and the car has done <5000 miles since I last did most of these a year ago, so I fear I have just thrown good money after bad. Will probably bite the bullet and book into a dealership for emission test and diagnosis next prior to trying full MOT retest. Bit of a pain as nearest is 20 miles away from me and now the old MOT has expired, as well as being potentially expensive for a car that's worth less than the likely bill.
If it helps, my '2 allways had a code 21 and passed emissions no probs, year after year.
IIRC there should be 5v or 0v between VF1 and E1 based on the ECU's reading of the O2 sensor rich/lean - obviousley this might be different since my book's for a mr2 but it says it should fluctuate 8 or more times in 10 seconds at 2500 RPM. (if the O2 sensor is working)
Hope this helps
Neil
IIRC there should be 5v or 0v between VF1 and E1 based on the ECU's reading of the O2 sensor rich/lean - obviousley this might be different since my book's for a mr2 but it says it should fluctuate 8 or more times in 10 seconds at 2500 RPM. (if the O2 sensor is working)
Hope this helps
Neil
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