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I wanted to get a general consensus about the rebuilt ECMs from SIA. I have a 92 manual and I would like to find a working ECM as a backup because these things are oddballs, or if I just use them for a rebuild. Anyway I was just looking for some advice to find a working 16159278, or the best way to get the current one fixed. It currently seems to have some quirks in it.
That was the feeling I was getting. Using the FSM tracing the codes I am getting two of them lead to a faulty ECM. Whatever the issue in the ECM I think its more than the standard reflow the board fix.
There are 4 things that happened about 2 weeks ago. They happened in this order.
Took the car for a ride, stop and go local streets ( 30 minutes coolant temp over 190F to 230F)
1. Noticed after the car was warmed up, didn't idle down like normal
2. In slow moving traffic with stop lights, changed the gauges to digital temp, I watched the gauges, got to 220F turned on the A/C no response.
3. Parked, temp hit 230F no fans
4. Drove home, jumped A/B fans did not come on, they always used to
Pulled codes, Code H69 A/C clutch relay
Code H32 ERG - which I know about Solenoid works, holds vacuum etc
IF I become the ECM, IGN on, pin the primary and secondary ground wires at the ECM, both fans come on as they should
IF I become the ECM, IGN on, pin the A/C clutch relay wire at the ECM , its clicks and locks like it should
So I know its not the relays, shorts etc, the ECM is just not sending the signal to ground the wires
Any ideas? Could it be something A/C related?
I jumped A/B and disconnected the A/C pressure sensor to see if it was something with that, the fans didn't come on
Checked the CTS gauge and the resistance is close to what it should be for the temp it was 4700 ohms
TPS - correct volts in the closed position 0.67V
My main issues where comm bus issues (ie ASR, ECM to CCM handshake etc) caused by the solder joints in the ECM.
Yours sounds different. I wonder if the ECM is not seeing the CTS voltage so thinks it’s cold all the time. But as you stated jumping pins and triggering AC should cause them to come on.
I would make extra sure your grounds are good.
Perhaps the ECM is commanding fans on but bad ground(s) are preventing….but you were able to trigger directly at the harness so…
If all else fails sending it to SIA they won’t charge you full price if they find nothing wrong. Your symptoms are odd and at least you ran through proper diagnostics in the FSM.
I think that is my best bet. I talked with SIA and they asked I add all the codes I was having so they can look into the circuits. I am at a loss for the cars negligent behavior. I took a good look at the EGR and I think it was allowing air into the intake due to a bad seat. It opens and closes with vacuum. I got a data-logger and my LTERM counts are high 150 - 160 not the 128 it should be. From what I have read that is a lean condition and it could be the EGR or IAC. I will start with the EGR replacement because I was getting a code for that. As far as the fans and the A/C clutch relay to the best of my understanding even if the freon was low ( the car was not converted) in A/B jump mode the fans should come on. Time will tell the car will be in winter hibernation soon enough and I will have plenty of time to scratch my head.
If anyone has any tests or idea as to what my issue is I am happy to try them.
SIA Electronics for an ECM
