Getting a P1652 code?

[3.8L Strong]

What is code P1652 all about? I tried to erase it but it won't erase. Anyone know? Thank you, Tommy.

[CTFirebird]

Re: Getting a P1652 code?

P1652 - Powertrain Induced Chassis Pitch Output Circuit. I don't know anything about it, but that might get you steered in the right direction.

[3.8L Strong]

Re: Getting a P1652 code?

I just found an article that someone posted elsewhere concerning his 1999 Chevy Malibu. It appears that the GM P1652 code relates to the (Cooling fan relay 2 and 3 control circuits.) Thought you would be interested in knowing that. At least I know where to look now. Thank you, Tommy.

[David8399]

Re: Getting a P1652 code?

Circuit Description
Output driver modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding ON. Unlike the quad driver modules (QDMs) used in prior model years, ODMs have the capability of diagnosing each output circuit individually. DTC P1652 set indicates an improper voltage level has been detected on ODM B output 2, which controls the high speed and series/parallel cooling fan relays.

Conditions for Setting the DTC
• The ignition is ON.

• An improper voltage level has been detected on the output circuit which controls the high speed fans.

• The above conditions are present for at least 30 seconds.

Action Taken When the DTC Sets
• The PCM will illuminate the MIL during the second consecutive trip in which the diagnostic test has been run and failed.

• The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.

Conditions for Clearing the MIL/DTC
• The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed.

• The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

• The DTC can be cleared by using the scan tool Clear Information function or by disconnecting the PCM battery feed.

Diagnostic Aids
Check for the following conditions:

• Poor connection at PCM - Inspect harness connectors for the following items:

- Backed out terminals

- Improper mating

- Broken locks

- Improperly formed or damaged terminals

- Poor terminal to wire connections

• Damaged harness - Inspect the wiring harness for damage.

• If the harness appears to be OK, disconnect the PCM, turn the ignition ON and observe a DMM connected between the Fan 2 driver circuit and ground at the PCM harness connector while moving connectors and wiring harnesses related to the series/parallel fan relay and the high speed fan relay. A change in voltage will indicate the location of the fault.

Review the Fail Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.

Normally, battery feed voltage should be present on the control circuit with the PCM disconnected and the ignition turned ON.

Checks for a shorted component or a short to B+ on the control circuit. Either condition would result in a measured current of over 500 milliamps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 milliamps.

Checks for a short to B+ on the cooling fan relay #2 and #3 control circuit.

This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.

DTC P1652 - Fan 2 Relay Control Circuit Step
Action
Value(s)
Yes
No

1
Was the Powertrain On-Board Diagnostic (OBD) System Check performed?
--
Go to Step 2
Go to the Powertrain On Board Diagnostic (OBD) System Check

2
Turn OFF the ignition switch.
Disconnect the PCM.
Turn ON the ignition switch.
Using a J 39200 DMM, measure voltage between the cooling fan relay #2 and #3 control circuit at the PCM harness connector and ground.
Is the voltage near the specified value?
B+
Go to Step 3
Go to Step 6

3
Disconnect the right engine cooling fan.
Connect the J 39200 DMM to measure current between the cooling fan relay #2 and #3 control circuit at the PCM harness connector and ground.
Monitor the current reading on the J 39200 DMM for at least 2 minutes.
Does the current reading remain between the specified values?
0.1 to 0.5 amps

(100 to 500 mA)
Go to Step 11
Go to Step 4

4
Disconnect engine cooling fan relays #2 and #3 (leave the PCM disconnected).
Reconnect the right engine cooling fan.
Using the J 39200 DMM, measure voltage between the the cooling fan relay #2 and #3 control circuit and ground.
Is voltage at the specified value?
0V
Go to Step 14
Go to Step 5

5
Locate and repair short to voltage in the fan 2 and 3 relay control circuit. Refer to Wiring Repairs .

Is action complete?
--
Go to Step 18
--

6
Turn OFF the ignition switch.
Check the battery feed fuse for the engine cooling fan relay #3 and engine cooling fan relay #2 coil.
Is the fuse open?
--
Go to Step 7
Go to Step 8

7
Locate and repair short to ground in the battery feed circuit for engine cooling fan relays #3 and #2. Refer to Wiring Repairs .
Replace the fuse.
Is action complete?
--
Go to Step 18
--

8
Disconnect engine cooling fan relay #2.
Turn ON the ignition switch.
Measure voltage between the relay coil battery feed circuit at engine cooling fan relay #2 cavity F5 and ground.
Is voltage near the specified value?
B+
Go to Step 9
Go to Step 13

9
Check the engine cooling fan relay #2 and #3 control circuit for an open or a short to ground.
If a problem is found, repair the engine cooling fan relay #2 and #3 control circuit. Refer to Wiring Repairs .
Was a problem found?
--
Go to Step 18
Go to Step 10

10
Check for the following conditions:

The engine cooling fan relay #2 and #3 control circuit for poor connections at the cooling fan relays.
The battery feed circuit for poor connections at the cooling fan relays.
The engine cooling fan relay #2 and #3 control circuit for a poor connection at the PCM.
Was a problem found?
--
Go to Step 18
Go to Diagnostic Aids

11
Turn OFF the ignition switch.
Reconnect the right cooling fan.
Reconnect the PCM.
Disconnect engine cooling fan relay #2.
Turn ON the ignition switch.
Connect a J 34142-B Unpowered test lamp between the cooling fan relay #2 and #3 control circuit at the right side cooling fan relay harness connector and B+.
Using the scan tool outputs test function, cycle fan 2 ON and OFF.
Does the test lamp flash ON and OFF?
--
Go to Diagnostic Aids
Go to Step 12

12
Check the cooling fan relay #2 and #3 control circuit for a poor connection at the PCM.
If a problem is found, replace faulty terminal. Refer to Wiring Repairs .
Was a problem found?
--
Go to Step 18
Go to Step 15

13
Locate and repair open in battery feed circuit to the cooling fan relay(s) coil. Refer to Wiring Repairs .

Is action complete?
--
Go to Step 18
--

14
Reconnect engine cooling fan relay #3.
Install the J 39200 DMM to measure current between the cooling fan relay #2 and #3 control circuit and ground.
Monitor the current reading on the J 39200 DMM for at least 2 minutes.
Does the current reading remain below the specified value?
0.25 amp

(250 mA)
Go to Step 16
Go to Step 17

15

Important:
The replacement PCM must be programmed. Refer to PCM Replacement/Programming .

Replace the PCM.


Is action complete?
--
Go to Step 18
--

16
Replace engine cooling fan relay #2.

Is action complete?
--
Go to Step 18
--

17
Replace engine cooling fan relay #3.

Is action complete?
--
Go to Step 18
--

18
Turn OFF the ignition switch.
Reconnect any relay, cooling fan, and PCM connectors that were disconnected in the previous step.
Turn ON the ignition switch.
Review and record scan tool Fail Records data.
Clear DTCs.
Operate the vehicle within Fail Records conditions as noted.
Using a scan tool, monitor Specific DTC info for DTC P1652 until the DTC P1652 test runs
Does the scan tool indicate DTC P1652 failed this ignition?
--
Go to Step 2
System OK

[3.8L Strong]

Re: Getting a P1652 code?

David, this is awesome! This is really good info. I'm not absolutely sure, however, I think this is the problem: I just installed a new PCM which was programmed by the same company that fabricated my engine harness. I think I should have had someone else do it. The reason is, since I installed the engine harness I have been troubleshooting electrical problems ever since. I have found wires crossed on 4 circuits. Several wrong wire connectors were installed for the sensors on the engine harness that I had to replace. I believe they used wire connectors from a later model Camaro, probably from a 2000 Camaro. My engine harness, PCM and all electrical wiring was suppose to be setup for a 98 Camaro with a 3.8 engine. So, as for the P1652 code setting, I'm almost positive that when they programmed this new PCM that I'm now using, they did not take into consideration the Fan 2 relay control circuit. The reason I say that is because with the first PCM that they programmed, I was not getting the P1652 code setting. The reason for replacing the PCM, with all of the crossed wiring that I had to correct, the original PCM got shorted out. Many of the systems was no longer working inside the PCM. Since then I have gone over the engine harness wiring with a fine tooth comb. I'm quite confident that I have found and corrected all of the crossed wiring, Except for: the IAC valve wiring. This is what I'm currently troubleshooting. The problem is, the electrical diagram in the GM Camaro repair manual shows the IAC wiring configuration for the 98 Camaro with a 3.8 V-6 engine to be one way, and the AllData wiring diagram shows it to be in a different configuration. I tried using both wiring configurations. For one of the wiring configurations the IAC valve heats up much faster than the other wiring configuration, this is after I start up the engine. The one that heats up faster gets so hot, that I cant even touch the valve with my fingers. With the other wiring configuration, the IAC valve still gets hot, however, I'm still able to touch with my fingers. So, the question is, which one is the right one to use. They are both for a 98 Camaro with a 3.8 V-6 engine. Do you have a diagram that I can compare with? If you do, can you email me that diagram to me at: Chevyone@hawaii.rr.com. I have also just taken a video of my troubleshooting process for the IAC valve. As soon as I can get it on a disk, I will get it loaded on a website somewhere for viewing. Would you know, or does anyone know, which website may be a favorite for viewing this type of video's? If I'm correct about the fan 2 programming from the PCM, is there a way to confirm it? Thank you for your outstanding support, Tommy.

[LETZRIDE]

Re: Getting a P1652 code?

Gunna bump this thread...

what is a DMM and what is this J 39200 ?

I am getting this code and have replaced the primary fan (which was dead) we jumped power to all the relay circuits and can have the fans come on when we put power to the fuse box where the relays would go.

For some reason however the car will not turn either fan on while on, or while commanded by hp tuners?

I dont exactly understand the context of this guide so who can give me a hand?

the relays have also been tested and you can hear them open and close when power is applied...

[LETZRIDE]

Re: Getting a P1652 code?

update (Im using this thread because of the relevant info already in it)

update...we tested the fuses under the hood, and every single fuse closest to the driver side fender have no power running to them...My horn included as it doesnt work at this time.

What would cause the entire driver side most column of 4 fuses to have no power running to them at all? Every other fuse in that block has power going to it?

[bigbrian442]

Re: Getting a P1652 code?

Do you have the MAXI fuse in that box?

[LETZRIDE]

Re: Getting a P1652 code?

what is that?

[LETZRIDE]

Re: Getting a P1652 code?

if you mean this?

Then ya, I have those kind of fuses, and the relays in that box...the entire driverside column of those fuses have zero power flowing to them, and from my understanding they should have power to one side of the fuse?

My horn also doesnt work as it is one of the fuses not being given power.

For this reason alone I am shying away from it being a bad pcm...

[bigbrian442]

Re: Getting a P1652 code?

They are like the smaller fuses and if they are good have power to both sides. Check the small wires coming off the + starter post. Older cars used a fuse able link there.

[LETZRIDE]

Re: Getting a P1652 code?

They are like the smaller fuses and if they are good have power to both sides. Check the small wires coming off the + starter post. Older cars used a fuse able link there.

where would I find them? I know all the other fuses in that box have power to one side of the slot...except for these 4 fuses furthest to the driver side (horn, fans, and 2 abs ones I believe)

And teh small wires coming off the starter post, do you mean the red post thing that sits above the battery?

[bigbrian442]

Re: Getting a P1652 code?

The fuses should have power to both test ports on the fuse top. If the fuse is in place and one side is hot the other side should also be hot. Only one side is hot if you are testing with the fuse remove from the block. The terminal block above the battery could also have wires with fuse able links as well as the + battery terminal on the starter it's self.

[LETZRIDE]

Re: Getting a P1652 code?

turns out a fusible link was severed...thanks guys!

[bigbrian442]

Re: Getting a P1652 code?

turns out a fusible link was severed...thanks guys!

Please post the location of the link that was blown in the event someone uses search.