2000 Z28 throwing code P1860

[Never-Enough]

Looking at buying a 2000 Z28, but wanted some insight on an issue it has beforehand. Owner says he replaced the TCC solenoid as the converter was unlocking at highway speeds. That fixed that problem, but he's had the CE light on for that code since then. What are the most likely culprits for this?

[pajeff02]

Triggers for that code occur when the PCM commands the solenoid "ON", 90 percent, and the voltage feedback remains high (essentially equal to whatever the charging system is putting out); or when the PCM commands the solenoid "OFF", 0 percent, and the voltage feedback remains low (zero volts).

First thing to check is your ENG CTRL fuse - should be a 15 amp fuse in the underhood electrical box. Most of the other diagnostic tests require a scan tool that can command the solenoid to turn on and off, checking wires for continuity and resistance, etc. Have you inspected the wire harness for damage?

[Never-Enough]

Triggers for that code occur when the PCM commands the solenoid "ON", 90 percent, and the voltage feedback remains high (essentially equal to whatever the charging system is putting out); or when the PCM commands the solenoid "OFF", 0 percent, and the voltage feedback remains low (zero volts).

First thing to check is your ENG CTRL fuse - should be a 15 amp fuse in the underhood electrical box. Most of the other diagnostic tests require a scan tool that can command the solenoid to turn on and off, checking wires for continuity and resistance, etc. Have you inspected the wire harness for damage?

I haven't inspected it yet. If it's not the fuse under the hood are we looking at big time PITA or money fix here?

[pajeff02]

If it turns out to really be a faulty solenoid, you probably have to open the transmission back up and remove the valve body to replace it. Unfortunately, new parts do not always equate to good parts. Could also be an issue with the internal wire harness on the transmission.

[Never-Enough]

If it turns out to really be a faulty solenoid, you probably have to open the transmission back up and remove the valve body to replace it. Unfortunately, new parts do not always equate to good parts. Could also be an issue with the internal wire harness on the transmission.

Could be solenoid, sure, but when the solenoid was replaced, it solved the issues w/the converter not locking up, but the CE light stayed on.

[pajeff02]

Interesting. When a P1860 code is set, it inhibits TCC engagement, freezes shift adapts from being updated, and can also inhibit 4th gear if it detects "hot mode".

[Never-Enough]

Interesting. When a P1860 code is set, it inhibits TCC engagement, freezes shift adapts from being updated, and can also inhibit 4th gear if it detects "hot mode".

So what's my best course of action?

[Never-Enough]

Triggers for that code occur when the PCM commands the solenoid "ON", 90 percent, and the voltage feedback remains high (essentially equal to whatever the charging system is putting out); or when the PCM commands the solenoid "OFF", 0 percent, and the voltage feedback remains low (zero volts).

First thing to check is your ENG CTRL fuse - should be a 15 amp fuse in the underhood electrical box. Most of the other diagnostic tests require a scan tool that can command the solenoid to turn on and off, checking wires for continuity and resistance, etc. Have you inspected the wire harness for damage?

Checked all the fuses in there & they are all good.

[pajeff02]

Apparently the PCM still thinks there is a problem. You'll need someone with access to a Tech II or similar to test the solenoid and see what is happening.

[Never-Enough]

Apparently the PCM still thinks there is a problem. You'll need someone with access to a Tech II or similar to test the solenoid and see what is happening.

That puts me SOL.

[pajeff02]

Not if the price is right. Selling the car with the SES light on could be an issue for him.

[Never-Enough]

Not if the price is right. Selling the car with the SES light on could be an issue for him.

I bought the car so it's my problem now.

[pajeff02]

How does it seem to you when you drive it?

[Never-Enough]

How does it seem to you when you drive it?

Drives perfectly fine.

[pajeff02]

I assume you have disconnected the battery or cleared the code?

[Never-Enough]

I assume you have disconnected the battery or cleared the code?

I did.

[pajeff02]

If you want me to email you the diagnostic for that DTC, PM me your email address and I can scan it this evening.

[Never-Enough]

If you want me to email you the diagnostic for that DTC, PM me your email address and I can scan it this evening.

PM sent. Thank you.

[pajeff02]

Email sent.

[antoine]

You sure its not 1870 code component slipping

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