1996 ECM thank you very much. now, checking the ECM physically, i have two slots for the connectors which matches the car's cabling. when i went to search on the internet, i found out that the ECM advertised for 1996-1997-1998 models have THREE slots for the ECM connector. what have gone wrong? i am sure, these are not compatible anymore since the connectors won't match. was there any modification done to the car. i bought it used.

TRUCK MEANS C1500 PICKUP?
NO SURE THE PROBLEM? IS THERE ONE?
THE MAF WIRE TO THE PCM SO IT CAN COMPUTER FLOWS AND MATCH INJECTION RATES TO IT.
MY GUESS IS YOU HAVE NO SERVICE MANUAL
NOR KNOW HOW TO TEST ANY MAF.
DID THE SCAN TOOL SHOW MAF DTC ERRORS?
MOST MAF AR3 3 PINS, GROUND , SIGNAL ,DC POWER.
MANUAL IS HERE
https://eautorepair.net/Marketing/Default.asp

I WILL PRESENT THE MAF PIN OUT.

12VDC POWER IS ING1 FUSE. BOX UNDERHOOD
B PIN IS GROUND
IT IS THAT SIMPLE.

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.

code p0353 refers to ignition coil C primary /secondary- circuit malfunction===causes --- wiring---ignition coil---ECM There is a possibility of ignition failure at a bad time for you. Replace the coil and check the wires and connections for dirty connectors. Have someone check the pins on the ECM for correct voltages as it may be a problem in the ECM

Solved by OP.
Further information on testing from Fixya Master Expert Larry Ng.

• K Berns Sep 12, 2013
• Well the problem ended up being the Ignition Switch.
• Thank you everyone for your help.
• 
  Larry Ng Jul 22, 2023
  bingo that, PICKUP TRUCK?>>>????????
  no the ECM is not shot, the power feeds are bad.
  a super simple problem in the hands of a person with DMM
  
  K1500 4wd
  1996
  ok here is the wiring
  
  Run FEEd ignition switch out.(or in)
  those 2 fuses are dead key off that is a fact
  seen in the service manual. schematics
  20amps and not blown
  
  the hot side is hot only key on
  that means the key switch is dead. if battery good.
  it cranks so power to the ignition switch is good and battery
  so the ignition switch is blown out.
  easy diagnosis.
  is the IP cluster dead., yes, ignition switch is bad
  the IGN switch sends power to cluster and engine controls
  

You have a defective battery.

REMOVAL & INSTALLATION

Print

OPERATION

When the term Electronic Control Module (ECM) is used in this guide it will refer to the engine control computer regardless that it may be a Vehicle Control Module (VCM), Powertrain Control Module (PCM) or Engine Control Module (ECM).
The Electronic Control Module (ECM) is required to maintain the exhaust emissions at acceptable levels. The module is a small, solid state computer which receives signals from many sources and sensors; it uses these data to make judgments about operating conditions and then control output signals to the fuel and emission systems to match the current requirements.
Engines coupled to electronically controlled transmissions employ a Powertrain Control Module (PCM) or Vehicle Control Module (VCM) to oversee both engine and transmission operation. The integrated functions of engine and transmission control allow accurate gear selection and improved fuel economy.
In the event of an ECM failure, the system will default to a pre-programmed set of values. These are compromise values which allow the engine to operate, although at a reduced efficiency. This is variously known as the default, limp-in or back-up mode. Driveability is almost always affected when the ECM enters this mode.

REMOVAL & INSTALLATION

See Figures 1 and 2

Fig. Fig. 1: ECM mounting scheme-except 1996 models

Fig. Fig. 2: ECM mounting scheme-1996 models
The ECM is located in the passenger side footwell in the kick panel up to 1996. In 1996, the ECM is located in the engine compartment next to the battery.

1. Disconnect the negative battery cable.
2. Disengage the connectors from the ECM.
3. Remove the spring retainer off and over the rail of the ECM on vehicles except 1996.
4. Slide the ECM out of the bracket at an angle.
5. Remove the ECM.

To install:

1. Install the ECM into the bracket.
2. Install the spring retainer (except 1996) and plug in the electrical connectors.
3. Connect the negative battery cable.

The ECM is located in a slot on the passenger's side of the firewall, under the hood. Look for the large connector and ground wire. Be sure to disconnect the negative battery cable, prior to removal or installation of the ECM.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

you have a wire problem. do you check the power source in the DTC connector and ecm wires to scan tool

That black plasict box with part number P/N: 136-2268 is a Audiovox car alarm brain. On one side it should have 4 individual connector slots. First one is a blue color for a 2 prong, second is a small white with 2 prongs, third is also white whith a 4 prong, and the last one is 2 prong is a off white color. The other side should have a long port for a 11 prong horizontal connector.

Sounds like your wire harness my have been shorted when you went through waters and the ECM is not reading the transmission and can not tell it when to shift.
Have the ECM scaned before the trasmission burn's out, and that's going to make you lose some sleeps.
Good luck and hope this helps. PS check the fuses, i believe there is a fuse for your transmissin or a relay.