Jeep Repair Problems? Ask a Mechanic for Answers ASAP
Hello, The wiring diagrams are not "continous" They are formated by specific circuits or componets - like this .[IMAGE][SRC][/SRC][ALT]tj808606[/ALT][WIDTH]100[/WIDTH][HEIGHT]100[/HEIGHT][STYLE][/STYLE][/IMAGE] There are at least 15 pages like this just for the cluster. What circuits do you need - or what are you trying to do?
Lets try again.
Ok- Thanks. I assume you have checked all the fuses ? We often see this problem when the engine computer fails or battery acid has damaged the wiring of the computer.
We test for a failing computer by moving the three connectors slightly to see if the engine will restart. We also look for acid damage to the wiring.Let me know if you want more info- I can send the diagnostics from the manual- It basically has you test the wires that communicate to the rest of the modules, test for power and ground at the computer connector- then replace the computer- Of course there are many other steps- but you need to have a scan tool that can read the engine and other modules- like the cluster and air bag , brakes, ect..Let me know what you find when you move the engine computer connectors. Thanks Scott.
Ok, I will send the info that I think will help the most.
Using a voltmeter as described will always show 12 volts unless the fuse is pulled that supplies memory power to the radio, air bag,computer, cluster. The 50 amp fuse must also supply the power for the memories.
The problem with the engine computer not communicating with the cluster can be caused by many different problem . The most often computer failure is caused by loose power connection inside the computer on the circuit board. Moving the connectors will sometimes cause the loose connection inside to reconnect - this would make the relays to click and the cluster to start working again.And the engine to start. The relays would only click if the key was on. Some computer failures will not respond to tapping the computer or moving the connectors. A Shorted sensor can cause the engine to not start.
On the rear of the engine on the drivers side valve cover there is a stud that can rub into the wiring harness, Inspect that area.
We test for shorted sensors by eliminating them one at a time. We start at the crank sensor, cam sensor, tps, map sensor ,o2 sensors ect.. We disconnect one sensor- cycle the key on check to see if the no buss returns- or we will connect the volt meter to the tps sensor and watch to see if the 5 volt supply returns after a sensor is disconnected. You will have to disconnect all the sensors one at a time.
I will gather more info, I will be back. Thanks Scott.
This is 1/5 of the info - more to follow. I read your post before I posted- I think you have a bad computer. Try tapping on it while some one cranks it over. Let me know if you need the other 4/5 of the dianostic for this
* ENGINE DOES NOT START & DRB DISPLAYS NO RESPONSE
NO RESPONSE DISPLAYED
ASD RELAY OUTPUT CIRCUIT SHORTED TO GROUND
DRB ADAPTER CABLE
FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN
PCM 5-VOLT PRIMARY SUPPLY CIRCUIT SHORTED TO GROUND
PCM 5-VOLT SECONDARY SUPPLY CIRCUIT SHORTED TO GROUND
TPS GROUND CIRCUIT SHORTED TO VOLTAGE
CAMSHAFT POSITION SENSOR
CRANKSHAFT POSITION SENSOR
GENERATOR SHORTED TO GROUND
OIL PRESSURE SENDING UNIT
SCI RECEIVE CIRCUIT OPEN
SCI RECEIVE CIRCUIT SHORTED TO GROUND
SCI TRANSMIT CIRCUIT OPEN
SCI TRANSMIT CIRCUIT SHORTED TO GROUND
MANIFOLD ABSOLUTE PRESSURE SENSOR
PCM DEFECTIVE (NO RESPONSE)
PCM GROUND CIRCUIT(S) OPEN
POWERTRAIN CONTROL MODULE (NS-6D)
VEHICLE SPEED SENSOR
FUSED B(+) CIRCUIT OPEN BETWEEN FUSE/BATTERY
FUSED B(+) CIRCUIT SHORTED TO GROUND
FUSED B(+) CIRCUIT OPEN BETWEEN FUSE/PCM
LEAK DETECTION PUMP
TEST ACTION APPLICABILITY
1 Key off.
Disconnect the Powertrain Control Module Black Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure both Ground Circuits at PCM Connector.
Is the resistance below 5.0 ohms at both Terminals?
Yes - Go To 2
No -Repair the open ground(s) at the Powertrain Control Module.
2 -Key off.
Turn ignition on.
Using a Voltmeter, measure the Fused Ignition Switch Output Circuit.
Is the voltage above 10.0 volts?
Yes -Go To 3
No - Repair the open Fused Ignition Switch Output Circuit between
PCM & Ignition Switch.
3 -Key off.
With a Voltmeter, measure the Fused B(+) Circuit in the PCM Connector.
Yes - Go To 4
No - Go To 13
4- Ignition Off
Disconnect the Throttle Position Sensor.
Ignition key on.
Connect a Voltmeter to the Throttle Position Sensor 5-Volt Supply Circuit.
Is the voltage below 4.0 volts?
Yes - Go To 5
No -Replace the Powertrain Control Module.
5 -Ignition Off
Disconnect the Camshaft Sensor.
Connect a Voltmeter to the Camshaft Position Sensor 5-Volt Supply Circuit.
Yes -Go To 6
No - Replace the Camshaft Sensor.
* ENGINE DOES NOT START & DRB DISPLAYS NO RESPONSE -
6 -Ignition Off
Disconnect the Crankshaft Sensor.
Connect a Voltmeter to the Crankshaft Position Sensor 5-volt Supply Circuit.
Yes Go To 7
No - Replace the Crankshaft Sensor.
Perform Powertrain Verification Test VER-1.
7 -Ignition Off
Disconnect the MAP Sensor.
Connect a Voltmeter to the Manifold Absolute Pressure Sensor 5-Volt Supply Circuit.
Yes - Go To 8
No - Replace the MAP Sensor.
8 - Ignition Off
Disconnect the Vehicle Speed Sensor.
Connect a Voltmeter to the Vehicle Speed Sensor 5-Volt Supply Circuit.
Read the Voltmeter.
Yes - Go To 9
No - Replace the Vehicle Speed Sensor.
9 - - Ignition Off
Disconnect the Oil Pressure Sending unit.
Read the voltmeter.
Yes - Go To 10
No - Replace the Oil Pressure Sending unit.
10 Ignition Off
Ignition On, Engine Not Running.
Measure the voltage of the Sensor Ground Circuit at TPS Connector.
Is the voltage above 1.0 volt?
Yes -- Repair the Sensor Ground Circuit shorted to voltage.
No - Go To 11
11--- Ignition Off
Disconnect the Oil Pressure Sending Unit.
Disconnect the Powertrain Control Module.
With an Ohmmeter, measure the resistance of the 5-Volt Primary Supply Circuit to
ground at the Powertrain Control Module Connector.
Is the resistance below 5.0 ohms?
Yes - Repair the shorted 5-Volt Primary Supply shorted to ground.
No - Go To 12
12 Ignition Off
With an Ohmmeter, measure the resistance of the 5-Volt Secondary Supply Circuit to
Yes - Repair the shorted 5-Volt Secondary Supply shorted to ground.
No - Go To 23