2000 GMC 2WD No communication @ OBD II connector - all ignition and ECM fuses good. Vehicle has 4" body lift - but no sign of torn grounds, etc.

obd II fuse located ???? Or do you mean fuse for DLC - the connector under the dash that you plug the scan tool into ? GIG LTR fuse 15 amp under hood fuse box

Error Code: DTC P1300
Description: Igniter Circuit Malfunction
Solution:
To repair the code please do the following:
1. Check spark plugs.
2. Check for open and short in harness and connector in IGF (Ignition Confirmation) signal circuit between ECM and igniter.
3. Disconnect igniter connector and check voltage between terminal IGF of ECM connector and body ground.
4. Check for open and short in harness and connector in IGT1 - 3 signal circuit between ECM and igniter.
5. Check voltage between terminals IGT1 - 3 of ECM connector and body ground.
6. Disconnect igniter connector and check voltage between terminals IGT1 - 3 of ECM connector and body ground.
8. Check for open and short in harness and connector between ignition switch and ignition coil, ignition coil and igniter.
9. Check and replace ignition coils with a good known one.
10. Check and replace ECM with good a known one .
Hope that works.
Thank you for visiting Fixya.

Turn you ignition switch to the on position ,does the CK ENG Lite appear, if yes this is a good indication. Your DLC (diagnostic link connector) should have battery voltage at pin 16 and ground at 4 and 5,If you can verify that your vehicle has this working order then its there problem and not yours

it is a 42, 96 on up use a OBD-II system to read codes. older than 96 use an OBD-I system to read codes. 42 means - electronic spark timing or bypass fault. this means that BYPASS line is open or grounded,
2) EST line is open or grounded
3) PROM or CALPACK not seated properly in the ECM
4) Poor connections between ignition module and ECM
5) Poor routing of EST harness and/or poor quality ignition wires (EMI induced electrical noise)
6) Faulty or incorrect ignition module
7) Faulty ECM.

DTC P1166: A/F Sensor (Sensor 1) Heater Circuit Malfunction

1. Reset the ECM/PCM.
2. Start the engine.

Is DTC P1166 indicated?

YES - Go to step 3.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at C101 (located under the right side of the dash), C401 (located under the left side of the dash), C402 (located under under the left side of the dash) the A/F Sensor relay, the A/F Sensor (Sensor 1) and the ECM/PCM.

1. Check the following fuse:

• No.14 OPTION (30A) fuse in under-hood fuse/relay box.
• No.2+B LAF HEATER (20A) fuse in under-dash fuse/relay box.
• No. 4ACG (10A) in under-dash fuse/relay box.

Are any of the fuses blown?

YES - Repair short in the wire between the A/F Sensor relay and the fuses.

NO - Go to step 4.

1. Measure voltage between ECM/PCM connector terminals A1 and A24, 30 seconds after the ignition switch is turned ON (II).

Is there battery voltage?

YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.

NO - Go to step 5.

1. Measure voltage between ECM/PCM connector terminals A22 and A24.

Is there battery voltage?

YES - Go to step 6.

NO - Go to step 10.

1. Turn the ignition switch OFF.
2. Disconnect ECM/PCM connector E (31P).
3. Turn the ignition switch ON (II).

1. Connect ECM/PCM connector terminal E8 to body ground with a jumper wire, then measure voltage between ECM/PCM connector terminals A1 and A24.

Is there battery voltage?

YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.

NO - Repair open or short in the wire between the A/F Sensor (Sensor 1) and ECM/PCM (A1).

1. Turn the ignition switch OFF.
2. Disconnect the ECM/PCM connector A (31P) and the A/F Sensor (Sensor 1) 4P connector.

1. Check for continuity between the A/F Sensor (Sensor 1) 4P connector terminal No.3 and body ground.

Is there continuity?

YES - Repair short in the wire between the A/F Sensor relay, A/F Sensor (Sensor 1) and ECM/PCM (A22).

NO - Go to step 13.

1. Turn the ignition switch ON (II).

1. Measure voltage between ECM/PCM connector terminals E8 and A24.

Is there battery voltage?

YES - Repair open in the wire between the ECM/PCM (A22) and the A/F Sensor (Sensor 1).

NO - Go to step 15.

1. Check for continuity in the wires between the A/F Sensor and the fuses.

Is there continuity?

YES - The wires are OK. Replace the A/F Sensor relay.

NO Repair open in the wire between the A/F Sensor relay and the fuses.

If the car is running fairly normally but just won't talk to the scan tool then what I usually find is that there is a blown fuse that powers one of the pins in the OBD-II scan tool connector. I don't have a diagram of which fuse it might be but that's where I would start looking. My scan tool gives me the dreaded "no data" message anytime one of these has lost power to the connector. You could have other issues including a faulty ECM but it's pretty rare for that to happen.

OK. Here's how to diagnose the P1298 error.

DTC P1298: ELD Circuit High Voltage

1. Reset the ECM/PCM (see HOW TO RESET THE ECM/PCM ).
2. Start the engine.
3. Turn on the headlights.

Is DTC P1298 indicated?

YES - Go to step 4.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the ELD and at the ECM/PCM.

4. Turn the ignition switch and headlights OFF.
5. Disconnect the ELD 3P connector.
6. Turn the ignition switch ON (II).
7. Measure voltage between body ground and ELD 3P connector terminal No. 1.

Is there battery voltage?

YES - Go to step 8.
NO - Check the No. 4 ACG (10A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair open in the wire between the No. 4 ACG (10A) fuse and the ELD.

8. Turn the ignition switch OFF.
9. Connect ELD 3P connector terminal No. 3 to body ground with a jumper wire.

10. Disconnect ECM/PCM connector E (31P).
11. Check for continuity between body ground and ECM/PCM connector terminal E15.

Is there continuity?

YES - Go to step 12.
NO - Repair open in the wire between the ECM/PCM (E15) and the ELD.

12. Check for continuity between ELD 3P connector terminal No. 2 and body ground.

Is there continuity?

YES - Go to step 13.
NO - Repair open in the wire between ELD and G201.

13. Reconnect the ELD 3P connector and ECM/PCM connector E (31P).
14. Start the engine and let it idle.
15. While measuring voltage between ECM/PCM connector terminals A24 and E15, turn the headlights on (high).

Does the voltage drop?

YES - Update the ECM/PCM if it does not have the latest software, or
substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Replace the ELD.

Your have a Fuel Pump A Control Circuit /Open try these possible solutions. Using a OBD II scan tool. Free use at Autozone. Check operation of fuel pump. Remove the glove compartment. Turn the ignition switch to ON. CHECK: Connect terminal FC of the ECM connector and the body ground. Check for the fuel pressure in the inlet hose when it is pinched by hand. OK:There is pressure in the fuel inlet hose. At this time, you will hear a fuel flowing noise .OK. Check for starter signal circuit Check for ECM power source circuit, if no good Repair or replace.OK Check circuit opening relay, if no good Replace circuit opening relay.OK. Check voltage between terminal FC of ECM connector and body ground to do this Remove the glove compartment Turn the ignition switch ON. Measure the voltage between terminal FC of the ECM connector and the body ground OK: Voltage: 9 – 14 V OK. Check for open in harness and connector between EFI main relay (Marking: EFI) and circuit opening relay, and circuit opening relay and ECM. Check fuel pump, if no good Repair or replace fuel pump.OK. Check for open in harness and connector between circuit opening relay and fuel pump, and fuel pump and body ground, if no good Repair or replace harness or connector.OK Check and replace ECM. Good luck and I really hope this solves that problem you are having. Please rate me. If you need further assistance you can always ask me.

OBD II connector troubleshooting 101

I had the same problem with my 2000 Elantra. the OBD II connector pins get squished and won't make cantact with the scan tool, therefore no connection. the solution is to bend the pins back so they will connect to the scan tool.


FIRST! check your lighter and radio fuses (which you have already done). If possible, make sure your scan tool is working properly, try it on another car. If it is functioning properly, remove the 2 screws holding the obd II connector to the dash. Look for obvious signs of corrosion, damage, or stuff that shouln't be in the connector (rocks, gum, etc.) clean the connector with a good electronics cleaner (I use the CRC stuff), you can usually find it at you local parts store, radio shack, or even wal mart. hose down the inside of the connector thouroughly and allow time to dry.

check for voltage between 4 (gnd) & 16 (+vcc) then 5(gnd) and 16(+vcc) with the ignition on the voltage should be between 12v-16v (these pins may be different on other cars, look for an OBD II connector pinout diagram if your car is different). If this voltage is not present at either pin, the problem is not the connector. check your fuses and wiring. if this voltage is present at both pins continue.

Here's what I did. with the connector free from the dash, you can see the back of the connector where the wires enter the connector. on either side of the connector there may be a white clip. pop both of them off. you should be able to push a small screwdriver or pick in that space to pull the pins back out towards the outside of the connector. do one at a time so you can tell if the pin has moved back out into position. do this for all of the pins. Try to connect. if still no luck try again to push out the pins and reconnect.

If your connection is restored, replace the clips, screw it back into the dash. Return your car to the lousy DMV where they will proceed to tell you something else is wrong which they neglected to tell you on your first 10 visits!! :-)

Stuff thats good to know:
some auto parts stores will connect their OBD II scan tool to you car for free. auto zone is one place
some times the computer will need to reset to restore a connection to the scan tool. to do this simply cycle the ignition off (wait a few seconds) then on again.
online auction places are a excellent resource for USB to OBD II connectors to connect your laptop to your car. there is lots of OBD II diagnostic freeware out there to go with your newly purchased connector.

Good Luck

Chris
-CL Systems

OBD 1.5 OBD 1.5 refers to a partial implementation of OBD-II which General Motors used on some vehicles in 1994 and 1995 (GM did not use the term OBD 1.5 in the documentation for these vehicles - they simply have an OBD and an OBD-II section in the service manual.)
For example, the 94-95 Corvettes have one post-catalyst oxygen sensor (although they have two catalytic converters), and have a subset of the OBD-II codes implemented. For a 1994 Corvette the implemented OBD-II codes are P0116-P0118, P0131-P0135, P0151-P0155, P0158, P0160-P0161, P0171-P0175, P0420, P1114-P1115, P1133, P1153 and P1158.[1]
This hybrid system was present on the GM H-body cars in 94-95, W-body cars (Buick Regal, Chevrolet Lumina ('95 only), Chevrolet Monte Carlo ('95 only), Pontiac Grand Prix, Oldsmobile Cutlass Supreme) in 94-95, L-body (Chevrolet Beretta/Corsica) in 94-95, Y-body (Chevrolet Corvette) in 94-95, on the F-body (Chevrolet Camaro and Pontiac Firebird) in 95 and on the J-Body (Chevrolet Cavalier and Pontiac Sunfire) and N-Body (Buick Skylark, Oldsmobile Achieva, Pontiac Grand Am) in 95.
Depending on the year and the vehicle, a car with the OBD 1.5 system may have either the older OBD-I connector, or the newer OBD-II connector, but they are electrically identical to each other.[citation needed]
The pinout for the ALDL connection on these cars is as follows:
Female OBD connector pinout 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 For ALDL connections, pin 9 is the data stream, pins 4 and 5 are ground and pin 16 is battery voltage.
Additional vehicle-specific diagnostic and control circuits are also available on this connector. For instance, on the Corvette there are interfaces for the Class 2 serial data stream from the PCM, the CCM diagnostic terminal, the radio data stream, the airbag system, the selective ride control system, the low tire pressure warning system and the passive keyless entry system.[2]
An OBD1.5 has also been used on Mitsubishi cars of '95 '97 vintage.
An OBD1.5 has been used in some 1995 Volkswagen VR6's (Juice Box's GTI)