Turn off service engine soon light on 1988 GMC s15

SOURCE: Truck losing power and service engine soon light on

Like to other guy said, give it a tuneup. Also try SEAFOAM to clean carb up of slug. Also check to make sure the butter fly for the choke has not come loose, causing it the choke it down. Failed choke pull-off.

Harvey N Tawatao

• 3854 Answers
• Posted on May 08, 2009

SOURCE: How do i clear the "service engine soon"

Disconnect the battery for a minuit and turn on the light's to power down any electrical power. Reconnect the battery and that should clear the "servie engine light soon",but if there are any DTC codes, the "Service engine light" will come back on.
On board diagnostic (OBD) was designed on vehicles equipped with electronic fuel injection so you can generally retrieve the codes yourself. No need buying a scanner or running to any parts stores to check the Engine Light. This system is called obd1 and applies to most vehicles made before 1995 for domestics and 1993 on imports.

For GM domestic vehicles made before 1995, the diagnostic connector is located under the dash panel by the driver side. To get the check engine codes to flash in your dash panel, use a jumper wire or a paper clip and connect terminals A and B of the diagnostic connector. Turn your ignition key on with engine off and the codes should start to blink. All codes should start with code 12 which is one long flash followed by 2 short flashes. This code 12 means the diagnostic system is normal and will repeat itself continuously if there are no trouble codes. Otherwise, code 12 will flash 3 times before flashing the fault codes.

the codes can be erased or cleared by disconnecting the battery negative terminal for 1 minute and reconnect. Just make sure to check your service manual in case you have electronic equipment such as radio or clock that needs reprogramming in which battery disconnection is not recommended. Finally after performing repairs on the culprit code, always go for a road test to confirm if the problem is fixed.

Good luck and hope this help, here is a link to the DTC codes. http://www.gmtuners.com/OBD1_DTC.htm

SOURCE: service engine light staying on

Hello tdamm...No...the service engine soon (SES) light on your yukon is not telling you to change the oil.
This is a warning light that is illuminated when there is a problem affecting the Emission system and the engines computer management (ECM) has detected it from a fault. It could be something as simple as a loose or defective gas cap. If the SES light is blinking, it's more serious....
The yukon needs to be connected to diagnostic equipment (scanner) for fault diagnosis.
You can go to autozone they will hook up an OBD II scanner to your vehicle and explain the codes to you.
Good luck...i hope this helps and will fixya up.

SOURCE: what causes service engine soon light to come on

This could be a number of things, that is why it is a good idea to have the engine codes read which many part stores offer for free.
The service engine light will go off if there is vaccum leaks, faulty sensors or circuits, or any electrical problems

ZJ Limited

• 17989 Answers
• Posted on Oct 05, 2009

SOURCE: firing order for a 1986 gmc s15

FIRING ORDERS

To avoid confusion, ALWAYS replace spark plug wires one at a time.

The most important thing to remember about the removal and installation of a distributor, cap or spark plug cable is that all wires MUST be labelled before they are disconnected. Keep in mind that these figures depict a firing order where the distributor cap terminals are relative to EACH OTHER only and they do not necessarily depict the tower positions in relation to the rest of the engine. This is true because any distributor which has been removed and reinstalled may have been installed with the No. 1 spark plug tower at any position (360 degrees) in relation to the rest of the motor, as long as the rotor aligned to the No. 1 tower when the No. 1 cylinder was at TDC of the compression stroke (valves closed, ready for the plug to fire). As long as the remaining wires were connected in the correct firing order sequence (depending on direction of distributor rotation) the engine will run. DO NOT EVER remove more than one wire from the distributor cap at a time unless you tag ALL wires and towers to assure proper installation.



Fig. 1: 1.9L engine . Firing order: 1-3-4-2 . Distributor rotation: counterclockwise



Fig. 2: 2.0L engine . Firing order: 1-3-4-2 . Distributor rotation: clockwise



Fig. 3: 2.5L engine . Firing order: 1-3-4-2 . Distributor rotation: clockwise



Fig. 4: 2.8L engine . Firing order: 1-2-3-4-5-6 . Distributor rotation: clockwise



Fig. 5: 4.3L engine. Firing order: 1-6-5-4-3-2 . Distributor rotation: clockwise

I hope help you with this (remember rated this help) Good luck.