Heated O2 Sensor Installed via Relay (Noisy problems)
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From: The Netherlands
Car: Cobra Kit Car
Engine: 350 HSR
Transmission: TKO 600
Axle/Gears: 3.31
Heated O2 Sensor Installed via Relay (Noisy problems)
I have installed a Heated O2 sensor (AFS74) according the diagram from Vader. (See picture)
I get a rattling relay every time that is switching, I have try several types of relay’s and the last one is a BMW stuff with a resistor between the connector 86 and 85.
My question is:
Is the signal coming from the A3 connector of the ECM intermittent? (Pulsing)
Do you have better experiences with this setup? Or do you have other solutions?
Regards,
Cobra289
I get a rattling relay every time that is switching, I have try several types of relay’s and the last one is a BMW stuff with a resistor between the connector 86 and 85.
My question is:
Is the signal coming from the A3 connector of the ECM intermittent? (Pulsing)
Do you have better experiences with this setup? Or do you have other solutions?
Regards,
Cobra289
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Joined: Nov 2003
Posts: 462
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From: Ft. Leavenworth, KS
Car: 83 TA, 89 TTA, others
Engine: ZZ4 TPI, LC2 turbo v6
Transmission: several, mostly broken
It'd be helpful if you'd remind us what ECM you're using, since the pinouts are different between most of them.
As far as the heater circuit goes, I'm not sure what you're trying to accomplish by grounding it through the ECM anyway. Why not just trigger the relay from any convenient "Hot in Run" or "Hot in Run or Start" circuit?
As far as the heater circuit goes, I'm not sure what you're trying to accomplish by grounding it through the ECM anyway. Why not just trigger the relay from any convenient "Hot in Run" or "Hot in Run or Start" circuit?
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From: Ft. Leavenworth, KS
Car: 83 TA, 89 TTA, others
Engine: ZZ4 TPI, LC2 turbo v6
Transmission: several, mostly broken
From your website, it appears that you're using a '165 ECM...so A3 should be the Charcoal Cannister Purge, and I'd expect it to be intermittent.
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From: The Netherlands
Car: Cobra Kit Car
Engine: 350 HSR
Transmission: TKO 600
Axle/Gears: 3.31
The ECM that I am talking about is the 165.
When he talks about “The circuit you show will work” he means the solution you mention.
However, I like that the heater is not active during long trips.
Regards,
Cobra289
Vader
The circuit you show will work. However, the heater will remain energized at all times. The circuits above will shut down the heater whenever the O² is providing an acceptable signal toe the ECM. The ECM will enable the EVAP canister purge only if the O² is active. On long trips, the heater will be off most of the time. Once the ECM is on closed loop and the car is under almost any kind of moderate load, the heater will be off.
On newer vehicles, the PCM itself has dedicated outputs to control the heaters so that they only operate when necessary. The two relay circuits emulate that system on the "old" ECMs.
The circuit you show will work. However, the heater will remain energized at all times. The circuits above will shut down the heater whenever the O² is providing an acceptable signal toe the ECM. The ECM will enable the EVAP canister purge only if the O² is active. On long trips, the heater will be off most of the time. Once the ECM is on closed loop and the car is under almost any kind of moderate load, the heater will be off.
On newer vehicles, the PCM itself has dedicated outputs to control the heaters so that they only operate when necessary. The two relay circuits emulate that system on the "old" ECMs.
However, I like that the heater is not active during long trips.
Regards,
Cobra289
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From: Ft. Leavenworth, KS
Car: 83 TA, 89 TTA, others
Engine: ZZ4 TPI, LC2 turbo v6
Transmission: several, mostly broken
Perhaps you should take a look at the CCP parameters in your bin file, then. From what I've seen, some bins enable and disable the CCP solenoid quite a lot in normal driving, so your relay would be toggling too.
On a side note, the OEM apps I'm personally familiar with, like my '96 Impala SS, and '97 Z28, do not employ any PCM control of the heater circuit, and don't seem to have any problems. But, I've only got about 220,000 miles between those two cars, so maybe I just haven't had a chance to notice it yet.
On a side note, the OEM apps I'm personally familiar with, like my '96 Impala SS, and '97 Z28, do not employ any PCM control of the heater circuit, and don't seem to have any problems. But, I've only got about 220,000 miles between those two cars, so maybe I just haven't had a chance to notice it yet.
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From: In reality
Car: An Ol Buick
Engine: Vsick
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Originally posted by Cobra289
However, I like that the heater is not active during long trips.
However, I like that the heater is not active during long trips.
They're good for over 100K miles, and draw little current.
Most folks typically just find a spot to tap into the fuse box, that gets power, key on, and run a 5A fuse to the heater.
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From: The Netherlands
Car: Cobra Kit Car
Engine: 350 HSR
Transmission: TKO 600
Axle/Gears: 3.31
Hi Dave,
That is what it happens the CCP solenoid is switched quite often (That’s is the reason of the noisy relay)
Hi Grumpy,
I don’t think that I will run 100K miles on the Cobra and definitely I want to get rid of the noise.
This view from and other angle has change my opinion guy’s.
Thanks,
Regards,
Cobra289
That is what it happens the CCP solenoid is switched quite often (That’s is the reason of the noisy relay)
Hi Grumpy,
I don’t think that I will run 100K miles on the Cobra and definitely I want to get rid of the noise.
This view from and other angle has change my opinion guy’s.
Thanks,
Regards,
Cobra289
Last edited by Cobra289; Jun 8, 2004 at 04:18 PM.
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From: STL area
disconnect ccp from the o2.!!!! There is no reason to run the heater on/off(or connect to ccp). As grumpy has stated, the heating element is good to 100k+ . So just wire the heating circut to switched power and call it a day.
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