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Registered
STS 1996, STS V 12007
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8 Posts
Discussion Starter #1
Dear Friends.-

Months ago I post a thread about a failure in my Caddy.-

The VATS are desabilitated; relays (ignition, fuel pomp and starter) are new; fusels are new, I put them 3 weeks ago, fuel pomp preasure is ok. The problem is the following.

Car turns on, 2 or 3 seconds after, turns off. The gasoline does not get to the inyectors; desconect battery 5 minutes, then conected again and the car turns on. After that, the same failure and now, the car does not turn on about one week ago.

BUT, know there is a noise back of the ingition module. That noise I can not described, but it hears when you put he key in ignition (it supose that it happens when the gasoline get to the inyectors), imagen you join letter "T" and "R".....trrrrrrrrrrrr, trrrrrrrrrrr something like that.

Cadillac tecnique personal have scanned the car but they tell me the computer does not show any problem.

May be some one can help me.

Regards.
 

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White Diamond '03 DHS (with DTS floor shift)
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86,623 Posts
The only thing behind the ICM that comes to mind is the PVC valve.
 

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Registered
STS 1996, STS V 12007
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8 Posts
Discussion Starter #5
But the PVC Valvue does not have anything to do with the problem; that is because the failure is that the car does not start any more.

On the other hand, I change the sparks and wire sparks, so their is energy in the ignition module.

The question is why the car does not start if the VATS is desabilited, fuel pomp's pressure is ok, relays (starter, inginition and fuel pomp) are new, fusels are new?
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,623 Posts
Check all four connections at the ICM and listen closely to try and locate that sound.
 

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Registered
1997 Seville STS, 2000 Seville STS
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1,694 Posts
If the car cranks at all then the VATS system is operating as designed or bypassed correctly. VATS disables the starter and the fuel injectors. So if you just added a resistor to the VATS unit input to replace the one in the key then VATS is not your issue. If you somehow bypassed the starter enable relay then VATS will still disable your injectors.

If the car starts and runs for 2 or 3 seconds then shutsdown it sounds more like an ignition switch problem, when you are loosing ignition power when the switch it released from start to run. Have you check all of your ignition fuses? There are at least 2 of them, labeled ignition 1 and 2 that feed different parts of the PCM and ignition circuits.
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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Car turns on, 2 or 3 seconds after, turns off. The gasoline does not get to the inyectors;
Fuel pump.
desconect battery 5 minutes, then conected again and the car turns on. After that, the same failure and now, the car does not turn on about one week ago.
Have you checked the fuel pressure again? Maybe the pump was failing and would only run for 2-3 seconds and now it has died.
 

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Registered
1997 Seville STS, 2000 Seville STS
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1,694 Posts
Heres the diagnostics for hard start;

Hard Start
Hard Start Symptom Step
Action
Value(s)
Yes
No

DEFINITION: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately stalls.

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

2
Perform a bulletin search.
If a bulletin that addresses the symptom is found, correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
--
Go to Step 20
Go to Step 3

3
Was visual/physical check performed?
--
Go to Step 4
Go to Visual /Physical check .

4
Check Engine Coolant Temperature (ECT) sensor for being shifted in value. With the engine completely cool, compare Engine Coolant Temperature to Intake Air Temperature.

Are ECT and IAT within the specified value of each other?
3°C (5°F)
Go to Step 8
Go to Step 5

5
Using a Scan Tool, display engine coolant temperature and view value.
Check resistance of engine coolant temperature sensor.
Refer to Engine Coolant Temperature Sensor Temperature vs. Resistance table.
Is resistance value near the resistance for the temperature noted?
--
Go to Step 7
Go to Step 6

6
Replace the ECT sensor.

Is action complete?
--
Go to Step 20
--

7
Locate and repair high resistance or poor connection in the ECT signal circuit or the ECT sensor ground.

Is action complete?
--
Go to Step 20
--

8
Check for faulty, plugged, or incorrectly installed crankcase ventilation valve.
If a problem is found, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 9

9
Check for water or alcohol contaminated fuel using J 39383-A. Refer to Fuel Check .
If a problem is found, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 10

10
Perform Fuel System Pressure Test .
If a problem is found, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 11

11
Visually/Physically inspect secondary ignition wires. Check for the following conditions:
Check all Ignition wire resistances; should be less than the specified value.
Ignition wires for cross firing.
Ignition wires arcing to ground.
Ignition wires for improper routing.
Spraying the secondary ignition wires with a light mist of water may help locate an intermittent problem. Ignition components will arc to ground when a secondary component is faulty.
If a problem is found, repair as necessary.
Was a problem found?
15K ohms
Go to Step 20
Go to Step 12

12
Check for proper ignition coil output voltage with spark tester J 26792 (ST 125):
Clip the spark tester J 26792 to engine ground.
Connect one end of a spark plug wire to the spark tester J 26792; connect the other end of the spark plug wire to the coil being tested.
Connect one end of another spark plug wire to the other coil tower; connect the other end of the spark plug wire to ground.
Crank the engine while observing the spark tester J 26792; a crisp blue spark should be observed.
Repeat the above steps for each coil.
If adequate spark is not present at all coils, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 13

13

Important
If spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.


Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. Refer to Ignition System .
If a problem is found, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 14

14
Check for loose ignition control module ground. Refer to Ignition System.
If a problem is found, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 15

15
Remove ignition coils and check the ignition coils for cracks or carbon tracking.
If a problem is found, replace affected coil(s) as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 16

16
Check ignition coil secondary resistance.
Replace any coil(s) which are not within the specified values.
Did any coil(s) require replacement?
5K - 8K ohms
Go to Step 20
Go to Step 17

17
Check IAC operation. Perform procedure in DTC P1508 diagnostic table.
If a problem is found, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 18

18
Check for the following Engine Mechanical problems: Refer to Engine Mechanical.
Low compression,
Leaking cylinder head gaskets,
Worn or incorrect camshaft
If a problem is found, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to Step 19

19
Review all diagnostic procedures within this table.
If all procedures have been completed and no malfunctions have been found, review/inspect the following:
Visual/physical inspection.
Scan Tool data.
Freeze Frame data/Failure Records Data.
All electrical connections within a suspected circuit and/or system.
If a problem is found, repair as necessary.
Was a problem found?
--
Go to Step 20
Go to the Powertrain (OBD) System Check

20
Operate the vehicle to duplicate conditions present when the original symptom was noted.

Is symptom still present?
--
Go to Step 3
Repair complete.
 
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