i had gotten the SES light the other night. my car had been sitting outside in the Chicago weather for about three months. it was about 50 outside on Thursday so i washed it and took it for a drive. everything was fine. good power, good idle, good temp, good oil pressure. car was running really strong. about 45 minutes in the drive, the SES light came on. i went to AutoZone and had the code scanned and cleared.

the code was 1661. i went online and found that the code is for ODMC Output 1 Circuit Faulty. does anyone know where i should start to troubleshoot this? i called my local dealership, and all they would say is to check the MIL fuse. thats fine and all, but it doesnt sound like it has anything to do with what the code is described as.

again, if anyone has any idea where i should start, i would really appreciate it. its for an OBD II car. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

and now i just found another description from a more reliable source that lists DTC Cod P1661 as MIL Control Circuit <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

 

I couldn't find anything on a code 1661. I checked my GM Tech service for a F-body and it isn't there. Sorry I couldn't help.

 

is it just 1661? or is it 1661b, c, or d? they are all different. this is what i am getting from my EASE library:
1661-MIL control circuit
1661b-ODMC output 1 circuit fail
1661c-check guages lamp control circuit
1661d-driver 3 line 1
sorry i couldn't be more help.

 

Lady, thanks for checking. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Texas, the girl at AutoZone didnt give me any designation like a b or c. just the P1661. either way, it sounds like they all have to do with the MIL Circuit. that also seems to be what everything ive found on the internet is saying.

but even if thats the case, where to i start to attempt to fix the problem? on Camaroz28.com, a member suggested changing a fuse. but how do i find out which fuse is bad?

 

Check all your fuses, 'specialy gauges & "crty" fuses. Does all the mil lights work? = They all do a bulb test at 2 different ignition positions, key on engine off, & cranking. The pcm uses a "driver" to activate the mil circuit.(malfuction indicator lamp) It monitiors this circuit & if inproper feedback at driver is recieved it will set this code . It should have 12v off & close to 0v volt on.

 

In SI2000 I looked up P1661 and got nothing. So then I put in "MIL Control Circuit" as you stated and here is what came up.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">DTC P0650 Malfunction Indicator Lamp (MIL) Control Circuit




Circuit Description
A voltage is supplied directly to the malfunction indicator lamp (MIL). The powertrain control module (PCM) controls the lamp by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the PCM. When the PCM is commanding a component ON, the voltage of the control circuit should be near 0 volts. When the PCM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be near battery voltage. If the fault detection circuit senses a voltage other than what is expected, the fault line status will change causing the DTC to set.

Conditions for Running the DTC
Engine speed is greater than 600 RPM.
The ignition voltage is between 6.0 volts and 16.0 volts.
Conditions for Setting the DTC
The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.
The conditions are present for a minimum of 10 seconds.
Action Taken When the DTC Sets
The PCM will not command the MIL ON. The PCM stores DTC P0650 in memory when the diagnostic runs and fails.
The PCM records the conditions present at the time the diagnostic fails to the Freeze Frame.
Conditions for Clearing the DTC
A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
Use a scan tool in order to clear the DTC.
Diagnostic Aids
If the ignition feed circuit is suspected of being open, check if other bulbs on that circuit illuminate.
Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame and/or Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate vehicle within the same Freeze Frame conditions (RPM, load, vehicle speed, temperature etc.) that were noted. This will isolate when the DTC failed.
Test Description
The numbers below refer to the step numbers on the diagnostic table.

Command both the ON and the OFF states. Repeat the commands as necessary.

If you do not find trouble in the control circuit or the connection at the PCM, the PCM may be faulty. However, this is an extremely unlikely failure.


Step 1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?
--
Yes: Go to Step 2
No: Go to Powertrain On Board Diagnostic (OBD) System Check

Step 2

Important
If the I/P is completely inoperative, refer to Instrument Cluster System Check in Instrument Panel, Gauges and Console for further diagnosis.

1) Turn ON the ignition leaving the engine OFF.
2) Command the lamp ON and OFF using the Scan tool.

Does the lamp turn ON and OFF with each command?
--
Yes: Go to Diagnostic Aids
No: Go to Step 3

Step 3
1) Turn OFF the ignition.
2) Disconnect the PCM connector C1 located on the opposite side of the manufacturer's logo. Refer to PCM Replacement/Programming .
3) Turn ON the ignition.

Is the lamp OFF?
--
Yes: Go to Step 4
No: Go to Step 5

Step 4

Probe the lamp control circuit in the PCM harness connector with a fused jumper wire connected to ground. Refer to Using Fused Jumper Wires in Wiring Systems.

Is the lamp ON?
--
Yes: Go to Step 6
No: Go to Step 7

Step 5

Repair the short to ground in the lamp control circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Yes: Go to Step 9
--

Step 6

1) Inspect for poor connections at the PCM. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
2) If you find a poor connection repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?
--
Yes: Go to Step 9
No: Go to Step 8

Step 7

Inspect for the following conditions:

- Faulty indicator
- Open ignition feed to the indicator
- Control circuit open or shorted to B+
- If you find a condition, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?
--
Yes: Go to Step 9
--

Step 8

Important:

Program the replacement PCM. Refer to PCM Replacement/Programming .

Replace the PCM.

Is the action complete?
--
Yes: Go to Step 9
--

Step 9

1) Select the Diagnostic Trouble Code (DTC) option and the Clear DTC option using the scan tool.
2) Idle the engine at the normal operating temperature.
3) Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
4) Operate vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test passed?
--
Yes: Go to Step 10
No: Go to Step 2

Step 10

Select the Capture Info option and the Review Info option using the scan tool.

Does the scan tool display any DTCs that you have not diagnosed?
--
Yes: Go to the applicable DTC table
No: System OK</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">

 

wow, thats awesome. thanks a ton to everyone who helped out in here. i appreciate it! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

now if that doesn't help you, burn the car and collect the insurance money! <img border="0" alt="[jester]" title="" src="graemlins/gr_jest.gif" />