Troubleshooting code PO753 ECM or PCM.

All those codes refer to the transmission on an automatic gearbox. Looks like there's a fault on the gearbox electrics.

P1765=Transmission 12 volt supply relay control circuit.
P0753=Shift Solenoid "A" Electrical
P0743=Torque Converter Clutch Circuit Electrical

P0688 (generic) = ECM/PCM Power Relay Sense Circuit /Open
P0688 DODGE - Auto Shutdown Relay Control Circuit Low

Check all the ECM fuses, if the fuses are OK try replacing the ASD (Auto Shut Down) relay.

Read more: http://www.autocodes.com/p0688_dodge.html#ixzz405J7vpq8

Possible causes:

- Weak battery - Low voltage while cranking
- Faulty Engine Control Module (ECM) relay
- Blown ECM fuse
- Faulty ECM
- ECM harness is open or shorted
- ECM circuit poor electrical connection

by the picture I'm assuming it is a dodge Dakota, must have engine light on, check codes, if you do not have a tool, go to auto zone, they will give you a print out for free. resend, if you have codes for misfire, cylinder 135 or 246 the PCM is junk.

ECM/PCM power relay control.

Symptom:

P-0753 TRANS 3-4 SHIFT SOLENOID/TRANS RELAY CIRCUITS

When Monitored and Set Condition:

P-0753 TRANS 3-4 SHIFT SOLENOID/TRANS RELAY CIRCUITS

When Monitored: Continuously with the key on.

Set Condition: This code is set if the voltage detected on the 3-4 Shift Solenoid Control

Circuit at the PCM is different than the expected voltage.

POSSIBLE CAUSES

FUSED B(+) FEED TO THE TRANS CONTROL RELAY OPEN

3-4 SOLENOID WIRING HARNESS INTERMITTENT DEF

3-4 SOLENOID WIRING HARNESS OBSERVABLY DEF

SHIFT SOLENOID CONTROL CIRCUIT OPEN

SHIFT SOLENOID CONTROL CIRCUIT SHORT TO GROUND

SOLENOID AND HARNESS DEF (SOLENOID CONTROL CKT)

TRANSMISSION RELAY OUTPUT CIRCUIT OPEN

TRANSMISSION RELAY OUTPUT CIRCUIT SHORTED TO GND

PCM DEF (3-4 SOLENOID/TRANSMISSION)

PCM DEF (TRANS 3-4 SOL/TRANS RLY CKT)

POWERTRAIN CONTROL MODULE DEFECTIVE

POWERTRAIN CONTROL MODULE DEFECTIVE

POWERTRAIN CONTROL MODULE DEFECTIVE

SOLENOID AND HARNESS DEF (SOLENOID PACK CONN)

TEST COMPLETE
TRANSMISSION CONTROL RELAY DEFECTIVE

P0685 DODGE - Auto Shutdown Relay Control Circuit Failure
Symptoms - Engine Light ON (or Service Engine Soon Warning Light)

Possible causes - ASD relay circuit is open or shorted
- Failed Auto Shutdown relay
- Failed ECM
Tech notes Check all the ECM fuses, if the fuses are OK try replacing the ASD relay. P0685 DODGE Description Short or open in Auto Shutdown (ASD) relay circuit

P0688 DODGE - Auto Shutdown Relay Control Circuit Low
Symptoms - Engine Light ON (or Service Engine Soon Warning Light)

Possible causes - ASD relay circuit is open or shorted
- Failed Auto Shutdown relay
- Failed ECM
Tech notes Check all the ECM fuses, if the fuses are OK try replacing the ASD relay. P0688 DODGE Description The Front Control Module (FCM) has detected the supply voltage below an acceptable value

try unhooking the neg battery cable for a couple minutes. It will reset the pcm and see if it comes back on.

transmision shift solaniod

On your first listing you under 04 durango. But now it makes more sense. On that year truck i have replaced the 3-4 shift solenoid for this code many times. You have to remove the valve body from the trans. The solenoid mounted on the valvebody.

did you check the fuseable link wire going from the starter to the alternator