Hi Guys, 

I've been intermittently having a check engine light and lately its been a little more steady. I pulled the cover on the dash and plugged in the white terminals to read the light on the ecu. 

92 Loyale EA82 with A/T non turbo

 

It sends the following: 

 

_ _ _ oo

 

_ _ _ oooo

 

_ _ o

 

So is that: 

 

32  O2 sensor

34 EGR Solenoid

21 Coolant Temp Sensor

 

Do I need to replace all of these sensors, or is one relate to the other? 

 

To know for sure you will have to get out a meter and check the resistance of the CTS against the service manual chart for resistance vs. temperature, check the EGR solenoid resistance against spec (around 35 ohms), and check for O2 sensor voltage switching (usually between about 250 and 750 millivolts) and/or check the O2 sensor heater circuit for continuity.

 

In all likelyhood you do need these sensors - they are all common failure items. But don't troubleshoot with VISA! TEST, VERIFY, REPLACE.

 

Having waited so long that you have three codes, you now have a much higher chance of these all being some kind of wiring issue like a grounding problem, etc. Have to rule it out with real diagnostics. The computer can't help with that part. It only gives a general direction (maybe the wrong one)

 

GD

I don’t understand your notations of dashes and o’s, what do they mean?

 

1. Clear the codes

2. Run vehicle

3. Check codes as soon as light trips again to see which one comes back first

4. Address that code first

I don’t understand your notations of dashes and o’s, what do they mean?

_ is the long flash

o is the short flash for the ECU codes

 

Simple and effective I thought

 

I'd be doing what idosubaru has suggested

 

Cheers

 

Bennie

Edited April 30, 20187 yr by el_freddo

_ is the long flash

o is the short flash for the ECU codes

 

Simple and effective I thought

 

I'd be doing what idosubaru has suggested

 

Cheers

 

Bennie

Thanks for the clarification Bennie. The morse code is what I was trying to communicate. 

To know for sure you will have to get out a meter and check the resistance of the CTS against the service manual chart for resistance vs. temperature, check the EGR solenoid resistance against spec (around 35 ohms), and check for O2 sensor voltage switching (usually between about 250 and 750 millivolts) and/or check the O2 sensor heater circuit for continuity.

 

In all likelyhood you do need these sensors - they are all common failure items. But don't troubleshoot with VISA! TEST, VERIFY, REPLACE.

 

Having waited so long that you have three codes, you now have a much higher chance of these all being some kind of wiring issue like a grounding problem, etc. Have to rule it out with real diagnostics. The computer can't help with that part. It only gives a general direction (maybe the wrong one)

 

GD

Thank you for this info. How do you test the CTS? I was thinking of heating the sensor in boiling water to measure resistance at temp?

Water test is good. I tested mine in car. Since it was still driveable, I just connected my ohm meter when I got home, and made a number of readings as the engine cooled down.

 

In my case, the resistance was jumping around, not gradually changing with temperature like it should be.