97 Yukon won't start

[Yukon97]

Started Yukon and it idled for two min. then just died. I saw the ECM-I fuse was blown and replaced it. Still won't start. Need help as I don't know too much about all the new electronics, I'm use to the old pre-computerized trucks. Thanks for any help

 

[SunlitComet]

that fuse covers all eight injectors, and power to ignition coil and coil driver, pcm and crankshaft sensor. A few of those should set a trouble code. See if you got any.

 

[LI99HOE]

Did the fuse blow again? If so, your going to have to do some wire tracing, and see what circuit has the low resistance to ground.
If the fuse didn't blow again, do like Jonathan said, and see if any codes were set that you can read.
Check condition of connectors by fuses, look for any bare wires...If you have 4 wheel drive... I have heard that there is a wiring harness on the driver side that the clamp breaks and allows the harness to be rubbed by the front drive shaft creating a short this will cause the ecm fuse to blow.
Don't know if this helps, but seems ya' got some investigating to do. Let us know.

 

[Yukon97]

No DTC stored in computer

Got an ODB reader and it states "no dtc codes stored in computer or freeze frame data. The fuse has not blown again but still won't start. I'm going to check for spark tonight. I just don't want to start buying a bunch of parts if they're not needed. The Yukon only has 52,000 mi. on it.

 

[LI99HOE]

Got an ODB reader and it states "no dtc codes stored in computer or freeze frame data. The fuse has not blown again but still won't start. I'm going to check for spark tonight. I just don't want to start buying a bunch of parts if they're not needed. The Yukon only has 52,000 mi. on it.

Warranty??

 

[Yukon97]

I wish but bought it used. Its a 1997. Did a carfax on it and it's the orig. mileage. I put 2,000 miles on it with no problems then it just went out.

 

[retorq]

I just don't want to start buying a bunch of parts if they're not needed.

That's why you get a scanner to get codes and a dummy light/voltmeter to test wires ...

 

[SunlitComet]

Testing and Inspection

IGNITION COIL TEST

• Make sure the ignition switch is "OFF."

1. Disconnect the distributor lead and wiring from the ignition coil. CAUTION : Do not Insert the J 39200 probe into the ignition coil connectors. The female terminals could be spread and deformed, resulting In intermittent operation of the coil. Be sure to make contact with only the front edge of the terminals.
2. Connect an ohmmeter as shown in Figure, step 1. Use the high scale. The reading should be infinite. If not, replace the coil.
3. Connect the ohmmeter as shown in Figure, step 2. Use the low scale. The reading should be 0.2 - 0.5 ohms. If not, replace the coil.
4. Connect the ohmmeter as shown in Figure, step 3. Use the high scale. The meter should read 5k - 25k ohms. If not, replace the coil.
5. Reconnect the distributor lead and wiring to the coil.

---------- Post added at 08:37 PM ---------- Previous post was at 08:35 PM ----------

Enhanced Ignition System Check

Enhanced Ignition System (System Check) (1 Of 3)

Enhanced Ignition System (System Check) (2 Of 3)

Enhanced Ignition System (System Check) (3 Of 3)

Enhanced Ignition System



SYSTEM DESCRIPTION
This system includes the Distributor, CAM position sensor ignition coil and ignition coil driver, secondary wires spark plugs, Knock (KS) sensors and crank sensors. The ignition system is controlled by the Vehicle Control Module (VCM). The VCM monitors the information from various engine sensors, computes the desired spark timing and controls the dwell and firing of the ignition coil via an Ignition Control (IC) line to the coil driver.

TEST DESCRIPTION
The numbers below refer to the step numbers in the diagnostic table.

The battery should be fully charged prior to any tests.

1. Perform the OBD system check before proceeding unless it was already performed. In order to disconnect the tachometer lead, it will be necessary to disconnect the gray ignition coil connector from the ignition coil and jumper the B terminal of the harness connector to the B terminal of the ignition coil using a fused jumper and terminal test adapter kit J 35616-A.
2. Checks for proper output from the enhanced ignition system. The spark tester requires a minimum of 25,000 volts to fire. This check can be used in case of an ignition miss, because the system may provide enough voltage to run the engine but not enough to fire a spark plug under heavy load. This test also separates the distributor cap, rotor and ignition wires from the ignition coil in order to help identify a secondary ignition system problem.
3. This step determines if the proper available voltage exists in the primary ignition circuit. Also checks ignition coil and wiring.
4. This check begins to determine if the VCM is providing a signal to the ignition coil module or not. If the VCM is not providing a signal to the ignition coil driver module, the problem exists between the distributor and VCM.
5. This test checks the coil driver module, connections and wiring.
6. This test checks the wiring from the VCM to the coil driver module and finally the VCM.

ENHANCED IGNITION SYSTEM (OVERVIEW)
A misfire condition could cause a rough idle or engine misfire condition. A DTC which determines it the misfire is random or specific to 1 or 2 cylinders will accompany the misfire. A worn Distributor cap and rotor, a cracked Distributor cap, cross fire within the Distributor or across plug wires or worn spark plugs may result in a misfire. A faulty or mispositioned crankshaft sensor which will also be accompanied by a crankshaft sensor DTC may also cause a misfire. If a DTC sets, refer to that chart first before using the Enhanced Ignition system check.