I have a 96 GMC Suburban that turns over with spark at the coil but has no spark at the plugs. I have replaced the coil and the ICM. What else could it be?

step one is test spark at coil first not distributor.(last)
the coil has a HV lug use spark wires HV + plug to test that this is first. if fails the distrib is bad, VR pick up.
s15 jimmy or PU
which engine,
2.5L 151cid L4
2.8L 173cid V6
4.3L 262cid V6 <<<< I will guess this and answer.

try new distributor.
and must be timed,
set engine, to TDC 0-degrees, #1 piston on firing stroke
step1 is that. so new dizzy super easy to put back same. time.

the ICM runs the coil but the ICM has inputs, that must be working
1988 uses what to make ICM work, good pickup coil
The PCM (VCM) runs the 4 wires to the Distributor and ICM in it.
if PCM is bad, or inputs to it are bad, there will be no spark
there is no CKP sensor here ,just CMP and CMP is the pickup coil inside DIZZy and connect to ICM and ICM makes spark. (ign coil)
the PCM I think only does spark timing advance.(called EST)
but no sure me how the 4 wires on PCM to Dizzy work.
a new pickup coil might fix this , (it is CMP named now)
CMP is cam sensor and here it is via cam to main DIZZy shaft to pickup coil)

Have you changed the spark plugs for new ones?

did it jump timing ?

change your coil.

I ASSUME its a 2.2l VIN "4"? Better be SURE you put in the correct crank. Different years have different tone wheels for the Crank Sensor. If it ran before, it should run now. I think 2 wire connector is for power to coils Power to Pink wire comes from IGN fuse A. Pink is 12V, Black is ground, 6 wire plug is for ICM.(bolted to base of coil pack) cant bench test anything. Should be a code 42 if cranked for 5 seconds and no start if its a CKP issue.

sl1 has single overhead cam sl2 has doubleoverhead cam

Hi and welcome to FixYa!

Looks like that the car's computer is faulty. This is a common problem on this vehicle. The engine is interconnected on the car's computer that when it's faulty something will surely fail, no wonder the engine is not running.

I strongly suggest that you go for a computer swap and observer how it goes.

Hope this helps and thank you for using FixYa! Have a good one!

Check the Ignition Control Module. Usually these are mounted in the base of the distributor - the distributor wire harness plugs into it. If you already changed that, then I would have the ECM ( Engine Control Module ) tested. I really hope it is the ICM - they are much cheaper than the ECM!!
Good luck and I hope this helps!!

Check to see if you have spark from the coil. Also take the fuel rail loose and turn the engine over a little to see if gas pumps out here.

Each ignition control module (ICM) has the following circuits:
An ignition 1 voltage circuit A chassis ground An ignition control circuit for each cylinder A low reference circuit
The PCM controls spark by pulsing the ignition control circuits to the ICM to trigger the coils and fire the spark plugs. The PCM and ICM are internally protected against shorts to power and ground on the ignition control circuits.

The spark plugs are connected to each coil by a short boot. The boot contains a spring that conducts the spark energy from the coil to the spark plug. The spark plugs are tipped with platinum for long wear and higher efficiency.


Ignition Control Module (ICM) Connectors



Fig. Ignition coil locations 2001-2004 4.8L, 5.3L, 6.0L Engines



Removal & Installation
2.2L (L61) Engine

1. Turn OFF the ignition.
2. Remove the accelerator cable from the bracket.
3. Remove the accelerator cable bracket bolt.
4. Remove the accelerator cable bracket.
5. Disconnect the ignition control module (ICM) harness connector.
6. Remove the ICM retaining screws.
7. Remove the ICM from the ignition coil housing.
   

To install:

1. Install the ignition control module in the ignition coil housing.
2. Install the ICM retaining screws. Tighten the retaining screws.
3. Connect the ICM harness connector.
4. Install the accelerator cable bracket.
5. Install the accelerator cable bracket bolt. Tighten the retaining screws.
6. Install the accelerator cable to the bracket.

2.2L (Ln2) Engine

1. Remove the air cleaner outlet from the air cleaner.
2. Remove the ICM electrical connectors (1) and spark plug wires (2).
3. Remove the ignition coils bolts (3).
4. Remove the ignition coils and ICM assembly.
5. Installation is the reverse of the removal procedure.
   

2.4L Engine

1. Disconnect the negative battery cable.
2. Remove the accelerator cable from the hold down clip.
3. Remove the cruise control cable, if applicable.
4. Remove the bolt from the fuel line retaining clip.
5. Disconnect the 11-pin harness connector for the ignition control module (ICM).
6. Remove the bolts from the ignition coil and the ICM assembly-to-camshaft housing.
7. Remove the ignition coil and ICM assembly from the engine.
8. Remove the screws that retain the housing to the cover.
9. Disconnect the coil harness connector from the ICM.
   CAUTION When removing the housing from the cover, make sure the ground strap stays in place.
   
10. Remove the housing from the cover.
11. Remove the screws that retain the ICM to the cover.
12. Remove the ICM from the cover.
    
    
    Fig. Removing the ICM from the camshaft cover
    

To install:

CAUTION DO NOT wipe grease from the module or coil if the same module is to be replaced. If a new module is to be installed, a package of silicone grease will be included with the module. Spread the grease on the metal face of the module and on the cover where the module seats. This grease is necessary for module cooling.

1. Install the ICM to the cover.
2. Install the screws that retain the ICM to the cover.
3. Install the ground strap, if necessary.
4. Connect the ignition coils connector to the ICM.
   CAUTION When installing the housing to the cover, make sure the ground strap stays in place.
5. Install the housing to the cover.
6. Install the screws that retain the housing to the cover.
7. Install the spark plug boots and the retainers to the housing, if necessary.
8. Install the ICM assembly to the engine while carefully aligning the spark boots to the spark plug terminals.
   CAUTION The ICM cover bolts must be installed using isolator washers with the rubber side facing down.
   
9. Install the bolts that retain the ICM assembly to the camshaft housing after coating the bolt threads with LOCTITE, or equivalent. Tighten the bolts to 16 ft. lbs. (22 Nm).
10. Connect the ICM 11 pin harness connector.
11. Install the bolt to the fuel line retainer clip.
12. Install the accelerator cable into the hold down clip.
13. Install the cruise control cable, if applicable. Connect the negative battery cable.

Hope this help (remember comment and rated this).