C5 P0352 Help please );
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,615
Likes: 4,062
From: Cape Coral, Florida
Sounds good I’ll go head give that a shot. My only questions are 1. dose it have be low impedance test light with the led, or will a normal test light be ok? 2. after I check continuity should. I put the battery back in and plug pcm back in aswell. I only ask cause I assume the brown low ref is grounded in pcm?
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 18
Likes: 3
Either an LED or incandescent test light will work…yes, reconnect the PCM connectors and battery before checking the low reference wire…the harness runs down behind the engine to you may be able to push on the harness with something long but won’t damage the harness…you may also want to clear the code if it’s still present…and I hope you are 100% certain you had the right wire at the PCM…do you need a pin out ??
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 18
Likes: 3
This is the voltage you will see on the control wire with the engine running…with a lab scope you will see roughly a 0-4 volt square wave…you may have a bad coil pack…if everything checks out good try swapping coil packs….yes, it may be a bad PCM but you want to make sure you’ve checked everything.
I just completed the continuity test. Ic 2 wire has continuity from the pcm connector to coil pack connector, measured 2.2 ohms. Measured continuity of cylinder 4 ic 4 wire from PCM connector for ic 4 green wire to coil pack connector for cylinder 4, to compare it also had continuity and measured 0.0-0.1 ohms.
About to move on to the test of the low ref brown wire and coil pack test now.
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 18
Likes: 3
Since you have the PCM connectors off find the control wire and with the ohm meter see if you have continuity between the PCM and the red terminal on the coil pack…just want to make sure you don’t have an open in the circuit…if you have a 12 volt test light connect it to B+ and probe the BROWN Low Reference wire which is a computer ground…the test light should light…I would try to wiggle the harness down to find the short to ground or to find an open…to do a coil pack “functional check” turn the key on and back probe the red wire with the connector installed…remove the plug wire off the coil pack and keep it about 1/2 inch from the coil pack…with a 12 volt test light connected to B+ tap on the control wire…the coil pack should fire !!…video below on my 2008 but these 4 wire coil packs all operate the same way.
Performed the coil function test by jumping b+ to red ic 2 wire coil fired.
Performed test to brown wire at coil pack connector. Connected test light to b+ and back probed brown wire with key on. When touching b+ to brown wire the test light lite up.
What should I check next voltage or hz at red ic 2 wire ?
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,615
Likes: 4,062
From: Cape Coral, Florida
I don’t measure a wire using resistance but odd you have 2.2 ohms vs the 0.1…maybe just high resistance on that wire…I think the only connector between the PCM and the coil pack is C110…like I said try wiggling the harness as this may be an intermittent problem…you would normally do a voltage drop across the connector but since it is pulse width modulated it would be hard to see what’s going into and out of the connector…you can try unplugging C110 and see if there is resistance going into it and then coming out…you can use the Hz or even voltage readings on the control as shown in my video…you need current flow to do a voltage drop and how I would check this is to put 12 volts into C110 on the control circuit and a headlight bulb on the other side of the connector connected to ground and now that you have current flow I would put my DVOM on either side of the connector and see how much the voltage is dropping.
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 18
Likes: 3
I don’t measure a wire using resistance but odd you have 2.2 ohms vs the 0.1…maybe just high resistance on that wire…I think the only connector between the PCM and the coil pack is C110…like I said try wiggling the harness as this may be an intermittent problem…you would normally do a voltage drop across the connector but since it is pulse width modulated it would be hard to see what’s going into and out of the connector…you can try unplugging C110 and see if there is resistance going into it and then coming out…you can use the Hz or even voltage readings on the control as shown in my video…you need current flow to do a voltage drop and how I would check this is to put 12 volts into C110 on the control circuit and a headlight bulb on the other side of the connector connected to ground and now that you have current flow I would put my DVOM on either side of the connector and see how much the voltage is dropping.
Okay I will go head give that a shot. I will say it dosent seem to be intermittent because that cylinder is pretty much dead zero spark. The only time it started sparking in that cylinder was after new pcm was installed. Then stoped after it was revved out for the crank relearn.
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 18
Likes: 3
I don’t measure a wire using resistance but odd you have 2.2 ohms vs the 0.1…maybe just high resistance on that wire…I think the only connector between the PCM and the coil pack is C110…like I said try wiggling the harness as this may be an intermittent problem…you would normally do a voltage drop across the connector but since it is pulse width modulated it would be hard to see what’s going into and out of the connector…you can try unplugging C110 and see if there is resistance going into it and then coming out…you can use the Hz or even voltage readings on the control as shown in my video…you need current flow to do a voltage drop and how I would check this is to put 12 volts into C110 on the control circuit and a headlight bulb on the other side of the connector connected to ground and now that you have current flow I would put my DVOM on either side of the connector and see how much the voltage is dropping.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 18
Likes: 3
I don’t measure a wire using resistance but odd you have 2.2 ohms vs the 0.1…maybe just high resistance on that wire…I think the only connector between the PCM and the coil pack is C110…like I said try wiggling the harness as this may be an intermittent problem…you would normally do a voltage drop across the connector but since it is pulse width modulated it would be hard to see what’s going into and out of the connector…you can try unplugging C110 and see if there is resistance going into it and then coming out…you can use the Hz or even voltage readings on the control as shown in my video…you need current flow to do a voltage drop and how I would check this is to put 12 volts into C110 on the control circuit and a headlight bulb on the other side of the connector connected to ground and now that you have current flow I would put my DVOM on either side of the connector and see how much the voltage is dropping.
I’m also going send back the new pcm as it has a warranty and have them check it out and check if the pcm ic2 driver is burned out.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,615
Likes: 4,062
From: Cape Coral, Florida
Do you think at this point I should just run a jumper wire from the pcm ic2 pin/connector to the c110? I’ve been alittle busy with work so I haven’t been able do voltage drop test yet. But other than that I’m not sure what else to test at this point.
I’m also going send back the new pcm as it has a warranty and have them check it out and check if the pcm ic2 driver is burned out.
I’m also going send back the new pcm as it has a warranty and have them check it out and check if the pcm ic2 driver is burned out.
Last edited by C5 Diag; Nov 13, 2024 at 08:39 AM.
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 18
Likes: 3
If you think it can rule out everything I can perform each test again while recording the procedure and results.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,615
Likes: 4,062
From: Cape Coral, Florida
Well it’s either an open, high resistance, or short to ground and can be intermittent…you’ll have to shake the wiring if intermittent and also a terminal tension test at the PCM, C110, and the coil pack should be performed.
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 18
Likes: 3
Just responding here in case anyone in future comes along this issue. I finally moved to new house and got some time off work to dig into this issue. I will also say be carful with continuity tests. My IC 2 wire had continuity and had voltage readings. But the issue ended up being an open ic 2 wire. I suspect the wire was holding on by 1 or two threads, because initial continuity test was good. But it most likely was not enough wire for correct amount of current to make it through. But after moving to my new home and runing through all diagnostic procedures again it had no continuity. Quite odd because before moving the continuity test passed multiple times. But it’s all fixed now ran a wire with a pcm pin and re pinned the pcm with it. And ran it to c110. Issue is fixed.