hey guys my problem is the i just bought a 2001 dts with 105000 miles, when i went to get it smoged it failed because the service engine soon light would not come on. he suggested i take it to the dealership but i dont want to spend that kind of cash for somthing like a bulb. anybody have any idea why my light wont come on not even when i turn the key to the on position. thanks for any help

I know GM has a bulletin about this somewhere...but I could not find it.

The SES lamp will not come on everytime at start up.

That being said, the SES lamp is not a bulb, it is LED.

In fact, the SES lamp has 2 LED's for redundancy.

The Cadillac service manual has you replace the cluster /IPC for a 'burned' out SES lamp.

'Led's last forever.' No, I've had to replace burned out LED's in my cluster. See picture. You can see the LED warning lamps on the top left corner of the circuit board. This picture is from my 2001 DTS cluster.

It can be repaired if you know what you're doing.


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More info...found the GM bulletin...


Subject: Normal Characteristics of Malfunction Indicator Lamp (MIL) During On-Board Diagnostic (OBD) Inspection/Maintenance (I/M) Testing


Models: 2007 and Prior Passenger Cars and Trucks (Including Saturn)

2007 and Prior HUMMER H2, H3

2007 and Prior Saab 9-7X




--------------------------------------------------------------------------------

The purpose of this bulletin is to inform dealers and OBD inspection/maintenance testing facilities of normal characteristics of the malfunction indicator lamp (MIL) and the engine or powertrain control module (ECM or PCM).

Some customers may comment on having been rejected or having failed an OBD emission inspection. In some cases, these vehicles do not need repair and may have been rejected or may have failed the OBD emission inspection due to a lack of understanding with regard to the normal characteristics of the MIL and ECM/PCM.

Following an engine run period, the MIL may not illuminate on an ignition OFF to ignition ON transition unless a 30 second delay is observed between key OFF and key ON. The delay is necessary on some control modules to allow the control module, either ECM or PCM, to power down. Most vehicles may require less time to achieve power down, but a 30 second delay will satisfy all known applications. This is normal operation for all GM control modules.

Some OBD I/M emissions test centers may not wait 30 seconds after a vehicle is turned off before proceeding with the MIL bulb check, which could result in a vehicle rejection or test failure.

To confirm proper MIL operation, wait 30 seconds after the ignition is turned OFF before proceeding with any key ON bulb check.




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thanks for the response. i checked after 30 seconds but still no light. is it possible something is not connected? i checked the fuses under the hood and under the rear seat all fuses are good. any other suggestions? thank you for the help

Maybe...both SES LED's burned out. Long shot..

Anyway, here is the service manual. Bet it scrambles once I post it..




Battery positive voltage is supplied directly to the malfunction indicator lamp (MIL). The powertrain control module (PCM) turns the MIL ON by grounding the MIL control circuit. There should be a steady MIL with the ignition ON and the engine OFF.

MIL Operation
The MIL is located on the instrument panel.

MIL Function
• The MIL informs the driver that a malfunction has occurred and the vehicle should be taken in for service as soon as possible.

• The MIL illuminates during a bulb test and a system test.

• A DTC will be stored if a MIL is requested by the diagnostic.

MIL Illumination
• The MIL will illuminate with ignition switch ON and the engine not running.

• The MIL will turn OFF when the engine is started.

• The MIL will remain ON if the self-diagnostic system has detected a malfunction.

• The MIL may turn OFF if the malfunction is not present.

• If the MIL is illuminated and then the engine stalls, the MIL will remain illuminated so long as the ignition switch is ON.

• If the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition switch is cycled OFF, then ON.

Diagnostic Aids
If the problem is intermittent refer to Intermittent Conditions

Test Description
The numbers below refer to the step numbers on the diagnostic table.

This step determines if the condition is with the MIL control circuit or the PCM.

This step determines if a voltage is constantly being applied to the control circuit.

No Malfunction Indicator Lamp (MIL) Step
Action
Yes
No

Schematic Reference: Engine Controls Schematics

1
Did you perform the Diagnostic System Check-Engine Controls?
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2
Inspect the Ign 1 fuse.

Is the fuse open?
Go to Step 10
Go to Step 3

3
Turn OFF the ignition.
Disconnect the PCM. Refer to Powertrain Control Module Replacement .
Turn ON the ignition, with the engine OFF.
Connect a 3 amp fuse jumper wire between the MIL control circuit and a good ground.
Observe the MIL.
Is the MIL illuminated?
Go to Step 9
Go to Step 4

4
Did the fuse in the jumper wire open?
Go to Step 11
Go to Step 5

5
Remove the instrument panel cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console.
Test the MIL control circuit for an open between the PCM and the IPC. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 14
Go to Step 6

6
Probe the MIL battery positive voltage circuit at the IPC harness connector with a test lamp connected to a good ground.

Does the test lamp illuminate?
Go to Step 8
Go to Step 7

7
Repair the open in the MIL battery positive voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
Go to Step 14
--

8
Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 14
Go to Step 12

9
Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 14
Go to Step 13

10
Repair the short to ground in the MIL battery positive voltage circuit. Refer to Wiring Repairs in Wiring Systems.
Replace the fuse.
Did you complete the repair?
Go to Step 14
--

11
Repair the short to voltage in the MIL control circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
Go to Step 14
--

12
Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console.

Did you complete the replacement?
Go to Step 14
--

13
Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?
Go to Step 14
--

14
Operate the system in order to verify the repair.

Did you correct the condition?
System OK
Go to Step 2




Logan Diagnostic LLC
www.ledfix.com
www.airbagcrash.com
www.logandieselusa.com