2004 Grand Caravan , 3.3 , auto . No crank - No start . I also do not hear the fuel pump turning on. Using Key off/on x3 method i show code p0688 . Which iam told is ASD Relay Sense Circuit Low.
For what its worth the van was running but had a slight low idle miss. Van was turned off by key and plug wires were removed from coil pack then reinstalled in correct place ... except one was left off ( didnt notice this till AFTER the issue started ) Iam thinking this caused the issue but not sure where / what to do next .

From reading , Iam trying to find a way to see if the asd relay prong is getting the ground from the ecm . Is there a way to do this at the fuse block under the hood ?

Heres what little ive checked so far :
1) Jumped starter relay prongs and starter engages ( did not try to start van only checked to see if starter worked and motor didnt lock up.
2) Swapped relays asd, starter ect
3) Check regular fuses

Iam not sure where to start = ignition switch - at relay power - at ecm - or where else .

Can someone guide me please

 

Symptom:
P0688-ASD RELAY SENSE CIRCUIT LOW
When Monitored and Set Condition:
P0688-ASD RELAY SENSE CIRCUIT LOW
When Monitored: With ignition key on. Battery voltage greater than 10 volts.
Set Condition: No voltage sensed at the PCM when the ASD relay is energized. One Trip
Fault.
POSSIBLE CAUSES
ASD RELAY
FUSED B+ CIRCUIT
ASD RELAY OUTPUT CIRCUIT OPEN (NO START)
IPM FUSE & RELAY CENTER
ASD RELAY OUTPUT CIRCUIT OPEN
PCM START
PCM
TEST ACTION APPLICABILITY
1 NOTE: Inspect the ASD Relay fuse located in the IPM. If the ASD Relay fuse
is open, repair the cause of the open first before continuing. Inspect theASD
Relay Output circuit for a short to ground for the cause of the open fuse.
NOTE: Diagnose P685 - Auto Shutdown Relay Control Circuit first if set
along with this DTC.
With the DRBIIIt, erase the DTC.
Attempt to start the engine. If the engine will not start, crank the engine for at least
15 seconds. It may be necessary to repeat several times.
Does the DTC reset.
All
Yes ! Go To 2
No !
2 Attempt to start the engine.
Does the engine start.
All
Yes ! Go To 3
No ! Go To 5
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the IPM C4 harness connector
Measure the resistance of the ASD Output circuit between the IPM harness
connector and the PCM harness connector.
Is the resistance below 5.0 ohms?
All
Yes ! Go To 4
No ! Repair the ASD Relay Output circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
4 If there are no possible causes remaining, view repair. All
Repair
Replace and program the Powertrain Control Module in accordance
with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
5 Turn the ignition off.
Install a substitute relay in place of the ASD Relay.
With the DRBIIIt, erase DTCs.
Attempt to start the engine.
With the DRBIIIt, read DTCs.
Does the DTC reset?
All
Yes ! Go To 6
No ! Replace the ASD Relay.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
6 Turn the ignition off.
Remove the ASD Relay from the IPM.
Using a 12-volt test light connected to ground, probe the Fused B+ circuit in the IPM.
Does the test light illuminate?
All
Yes ! Go To 7
No ! Replace the IPM Fuse & Relay Center.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
7 Turn the ignition off.
Remove the ASD Relay from the IPM.
Disconnect the PCM harness connector.
Disconnect the IPM C4 harness connector.
Measure the resistance of the ASD Relay Output circuit between the IPM harness
connector and the PCM harness connector.
Is the resistance below 5.0 ohms.
All
Yes ! Go To 8
No ! Repair the ASD Relay Output circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
TEST ACTION APPLICABILITY
8 NOTE: Ensure the IPM C4 harness connector is connected to the IPM.
Turn the ignition off.
Disconnect the PCM harness connector.
Measure the resistance of the ASD Relay Output circuit between the IPM and the
PCM harness connector.
Is the resistance below 5.0 ohms?
All
Yes ! Replace and program the Powertrain Control Module in accordance
with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No ! Replace the IPM Fuse & Relay Center.
Perform POWERTRAIN VERIFICATION TEST VER - 5.