New Member, Need AC Advice Please
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
If EVERYTHING is working correctly in the AC circuit and the sensor is not working the AC compressor will not come on…how exactly did you check the ground ??..that ground is a ground at all times…if you have no ground at the sensor you will have to check AT the PCM…you may have a broken wire between the PCM and the sensor or just a bad terminal at the sensor.
Heel & Toe
Joined: Sep 2005
Posts: 18
Likes: 1
From: North Port, Fl
If EVERYTHING is working correctly in the AC circuit and the sensor is not working the AC compressor will not come on…how exactly did you check the ground ??..that ground is a ground at all times…if you have no ground at the sensor you will have to check AT the PCM…you may have a broken wire between the PCM and the sensor or just a bad terminal at the sensor.
I did a continuity test with VOM between Bat neg and pin in sensor plug. Open circuit.
could I have accidentally discus ground when removing the accumulator and compressor when repairing the sys?
put in new accumulator, compressor, orifice tube and pressure sensor.
I also started to get a traction control solenoid and relay error message on the dash display.
other work done before the AC repair was replacing the knock sensor’s with the NAPA sensors which were fine installed but is back to low signal codes on bank 1 and 2.
Any connections to those new issues?
thank you for help
Last edited by owlhh; Sep 14, 2024 at 08:42 AM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,629
Likes: 4,074
From: Cape Coral, Florida
Thank you for the quick response
I did a continuity test with VOM between Bat neg and pin in sensor plug. Open circuit.
could I have accidentally discus ground when removing the accumulator and compressor when repairing the sys?
put in new accumulator, compressor, orifice tube and pressure sensor.
I also started to get a traction control solenoid and relay error message on the dash display. Any relation?
thank you for help
I did a continuity test with VOM between Bat neg and pin in sensor plug. Open circuit.
could I have accidentally discus ground when removing the accumulator and compressor when repairing the sys?
put in new accumulator, compressor, orifice tube and pressure sensor.
I also started to get a traction control solenoid and relay error message on the dash display. Any relation?
thank you for help
Heel & Toe
Joined: Sep 2005
Posts: 18
Likes: 1
From: North Port, Fl
Get yourself a 12 volt Incandescent test light (with a bulb) and connect it to battery positive and see if the test light illuminates when probing the ground wire at the pressure sensor…if no good go down to that PCM wire and try it there….if good at the PCM you have a break in the wire…if you have something to back probe the ground terminal at the sensor you can take a length of wire and connect it between the sensor and a good ground and see if the compressor functions.
Ok. Thank you. I will try that
If that works, then back to checking the wire to PCM?
where does the PCM get it’s grounds?
could I have accidentally disconnected one?
Are there any ground connections near the accumulator?
Just thinking back to what I moved replacing the accumulator and compressor.
Last edited by owlhh; Sep 14, 2024 at 09:27 AM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,629
Likes: 4,074
From: Cape Coral, Florida
As I had previously mentioned in a post I included a picture of the 4 PCM ground wires that go to engine block…refer to that.
Heel & Toe
Joined: Sep 2005
Posts: 18
Likes: 1
From: North Port, Fl
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Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,629
Likes: 4,074
From: Cape Coral, Florida
Heel & Toe
Joined: Sep 2005
Posts: 18
Likes: 1
From: North Port, Fl
Thanks
i am new to the site and forum
iI see you are from Fl
I am in North Port Fl
Last edited by owlhh; Sep 14, 2024 at 12:08 PM.
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
Being that you're new it's a good idea to fill out your profile with model year, mods, etc... and even location as there may be someone in your area that can help...all I see in your profile you live in the U.S. and you're a male....also not a good idea to "hijack" this thread...start a new one as that gives you more visibility with your problem....I see you joined in 2005 !!
Heel & Toe
Joined: Sep 2005
Posts: 18
Likes: 1
From: North Port, Fl
Being that you're new it's a good idea to fill out your profile with model year, mods, etc... and even location as there may be someone in your area that can help...all I see in your profile you live in the U.S. and you're a male....also not a good idea to "hijack" this thread...start a new one as that gives you more visibility with your problem....I see you joined in 2005 !!
I will be filling out the rest of my profile.
I was able to locate a bad ground to frame connection. Now have a solid ground reading.
still no luck. Compressor will not engage only if you jumper the relay.
still get a P0530 code. This one has me stump.
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
It’s a fairly simple circuit to diagnose…did you check with a test light at the PCM that the ground is good there ??…which ground did you fix ??…if it’s not associated with the AC Pressure Sensor you really didn’t accomplish anything…if you want to bring the car down here I can look at it for you….do you know how to back probe a connector wire ??…like I said you can “bypass” the sensor ground wire at the sensor connector with a length of wire and see if the clutch engages…do you understand what I’m trying to have you do ??…also if you can pierce the ground wire about an inch from the connector see if the test light illuminates…you just may have a bad connection AT the connector.
Last edited by C5 Diag; Sep 15, 2024 at 03:56 AM.
Heel & Toe
Joined: Sep 2005
Posts: 18
Likes: 1
From: North Port, Fl
It’s a fairly simple circuit to diagnose…did you check with a test light at the PCM that the ground is good there ??…which ground did you fix ??…if it’s not associated with the AC Pressure Sensor you really didn’t accomplish anything…if you want to bring the car down here I can look at it for you….do you know how to back probe a connector wire ??…like I said you can “bypass” the sensor ground wire at the sensor connector with a length of wire and see if the clutch engages…do you understand what I’m trying to have you do ??…also if you can pierce the ground wire about an inch from the connector see if the test light illuminates…you just may have a bad connection AT the connector.
https://youtu.be/g2ST8w_0w-Q?si=8vRokYsDl073QSnR
https://youtu.be/g2ST8w_0w-Q?si=8vRokYsDl073QSnR
next I was thinking to back probe the sensor connector while hooked to the sensor to ck the output signal. Seems to me the computer is not getting some other verification that it is ok to initiate the ground to turn the relay on. When jumping the relay, I see the computer thinks the compressor clutch is turning on.
where are you located?
I completed my profile
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
I found that when I wiggled the ground lugs at frame under the battery I was able to see the ground connection come back to the pine on the pressure sensor. I removed the ground wires, cleaned and replaced the lugs. Now reading a solid ground. I have been using a DOM. Still no charge with the AC. Still same code P0530.
next I was thinking to back probe the sensor connector while hooked to the sensor to ck the output signal. Seems to me the computer is not getting some other verification that it is ok to initiate the ground to turn the relay on. When jumping the relay, I see the computer thinks the compressor clutch is turning on.
where are you located?
I completed my profile
next I was thinking to back probe the sensor connector while hooked to the sensor to ck the output signal. Seems to me the computer is not getting some other verification that it is ok to initiate the ground to turn the relay on. When jumping the relay, I see the computer thinks the compressor clutch is turning on.
where are you located?
I completed my profile
Thanks and if you look at my profile I’m in Cape Coral….there are no grounds under the battery tray which are associated with the pressure sensor…what are you reading to indicate you have a solid ground ??…a good low reference or sensor ground has less than 100mv’s when the circuit is loaded (ie..car running) using a ground to ground voltage drop test…if you were to jumper the AC clutch relay allowing the compressor to turn what voltage reading are you seeing at the signal wire at the sensor by back probing it ??…you should see about 2.8 volts…if the compressor is not turning you should see around 1.65 volts key ON and that is the voltage based on the ambient temp…if temp is 90 degrees there should be 90 psi on the system…if the sensor is good but AC still not turning on there may be another input missing or skewed like the ambient air temp sensor…if the computer “thinks” it’s below freezing the clutch will not engage.
Last edited by C5 Diag; Sep 15, 2024 at 11:32 AM.
Heel & Toe
Joined: Sep 2005
Posts: 18
Likes: 1
From: North Port, Fl
Thanks and if you look at my profile I’m in Cape Coral….there are no grounds under the battery tray which are associated with the pressure sensor…what are you reading to indicate you have a solid ground ??…a good low reference or sensor ground has less than 100mv’s when the circuit is loaded (ie..car running) using a ground to ground voltage drop test…if you were to jumper the AC clutch relay allowing the compressor to turn what voltage reading are you seeing at the signal wire at the sensor by back probing it ??…if the compressor is not turning you should see around 1.65 volts.
I did, you are not far away.
I pulled the battery looking for ground points tracing down neg battery cable came to at stud on the frame multiple black wires tied ther so I started loosening and got a ground connection showing up on the pressure sensor plug ground position
I will see about back checking the signal wire today to ck the reading. The sensor is new but that doesn’t mean anything. could be bad
Is that the only other sensor in that loop with the P0530 error message?
where is that sensor located?
the outside temp reading on inside display looks ok
thank you for all the help
Last edited by owlhh; Sep 15, 2024 at 09:26 AM. Reason: More information
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,629
Likes: 4,074
From: Cape Coral, Florida
I did, you are not far away.
I pulled the battery looking for ground points tracing down neg battery cable came to at stud on the frame multiple black wires tied ther so I started loosening and got a ground connection showing up on the pressure sensor plug ground position
I will see about back checking the signal wire today to ck the reading. The sensor is new but that doesn’t mean anything. could be bad
thank you for all the help
I pulled the battery looking for ground points tracing down neg battery cable came to at stud on the frame multiple black wires tied ther so I started loosening and got a ground connection showing up on the pressure sensor plug ground position
I will see about back checking the signal wire today to ck the reading. The sensor is new but that doesn’t mean anything. could be bad
thank you for all the help
Do you have a scan tool where you can look at the sensor voltage ??
To check the wiring I disconnect the connector…with DVOM check the 5 volt reference to the low reference ground…I should see 5 volts…next jump the 5 volt reference to the SIGNAL wire…scan tool should show 5 volts…if I see these 2 quick checks the wiring is good !!
…if your wiring is good where did you buy your pressure sensor ??
Last edited by C5 Diag; Sep 15, 2024 at 09:08 AM.
Heel & Toe
Joined: Sep 2005
Posts: 18
Likes: 1
From: North Port, Fl
Do you have a scan tool where you can look at the sensor voltage ??
To check the wiring I disconnect the connector…with DVOM check the 5 volt reference to the low reference ground…I should see 5 volts…next jump the 5 volt reference to the SIGNAL wire…scan tool should show 5 volts…if I see these 2 quick checks the wiring is good !!
…if your wiring is good where did you buy your pressure sensor ??
To check the wiring I disconnect the connector…with DVOM check the 5 volt reference to the low reference ground…I should see 5 volts…next jump the 5 volt reference to the SIGNAL wire…scan tool should show 5 volts…if I see these 2 quick checks the wiring is good !!
…if your wiring is good where did you buy your pressure sensor ??
wish I did What would you recommend?
I did check the plug for the 5 v ref and it is there. Plus Ground good now
Bought AC Delci from O Riley