96 Dakota No Fire

[78clubcab]

I let my stepson take my 96 Dakota for a long trip and it broke down 150 miles from home. Thank god for triple A! Anyway, back in my driveway I checked for spark at number one cylinder, and found nothing. Next, I checked for spark at the coil and also nothing, so I thought gotcha!

I replaced the coil.......same thing, no spark. I tried to test for power to the coil but cannot get anything definitive. By this I mean I have a 1999 Durango 5.2 that runs fine and the coils are almost identical but there is a slight difference in the way they plug in to the working harness. With the key in run on both vehicles it is difficult to get a reading with a multimeter on the harness. Both vehicles read about the same, which is barely anything... About 1/100 of a volt.

I have heard of a lead light test on the ground side of the coil plug in where the lead light will pulse during cranking. I haven't tried this on the running truck, but I can't get the dead Dakota to do this.
In my frustration, I must confess I threw a part at this problem by replacing the crank position sensor. I did this because I was told by a friend this would kill the truck on the highway and cause no spark. It was also fairly cheap and an easy replacement. Guilty as charged!
I have a pickup coil new but don't want to throw it at the problem, too, so I haven't yet.

Where do I go from here? Positively no spark. Remember this truck died on the highway at speed of 65-70 mph. It is a 3.9 v6 auto 4wd

[Cheyenne Dave]

I believe this year truck is capable of self-diagnosis. I think you can cycle the ignition switch 3 times and then read the blinking ignition lamp on the instrument panel, like Morse Code. If you have a Haynes or Clilton manual for this truck, there is a decoding section which will help you interpret the flashes and perhaps help you diagnose the problem.

CD

[78clubcab]

Thanks for the reply! I tried my obd2 scan tool and says unable to connect. Possible computer problem? I will try the key as you said, too. I have the Haynes manual for this truck if that works.

[Cheyenne Dave]

A scan tool is way more advanced than my suggestion. Could be a computer issue. Perhaps others will offer other suggestions.

CD

[Chewie]

Thanks for the reply! I tried my obd2 scan tool and says unable to connect. Possible computer problem? I will try the key as you said, too. I have the Haynes manual for this truck if that works.

Scan II tool might be too new for your model. The key switch/flashing light has been reliable enough for me.
Same thing happened to my 93 Dak. I replaced the coil. No fire. Did the cap/rotor/wires next. Fired right up.
Ran fine after that until my brake lines rusted through and I put my foot through the floorboard trying to stop...!

[78clubcab]

Got it started today. The battery was getting weak so I put a charger on it Monday and noticed the coil power lead was unplugged when I took the battery charger off. I thought about how it had been raining on and off when I changed out the crank position sensor and how I had unplugged the coil lead to test for power. I wondered because of the rain if I had been in a hurry with the crank sensor and not plugged the coil in. I plugged in the coil and also gave a spray of gas down the airhorn just in case it might be fuel related. Put air cleaner assembly back on, hit the key and it was running just fine! Road test went fine as well, but I am going to test the old crank sensor with a multimeter . I think there is a way to do that. Then I will know for sure it was the crank sensor.

[78clubcab]

Update: I must have had the coil plugged in originally. Took the truck for a drive in the rain and didn't make it far before I turned around for home. It began to buck. I took it home and it stalled in the drive and wouldn't restart. The next morning it fired right up, though. I sprayed the distributor cap and wires with a spray bottle but truck still seemed to run fine. Then I sprayed and area of the wiring harness behind the battery but the relay box and the truck began to miss and stalled. I thought gotcha!. I then took covering off wiring harness and all looked fine. I checked all splices and all had power on both sides. Cap and rotor were extremely worn and wires were OK but not great so I replaced everything. Still no start. Spark issue persists! I think that given a week to dry out it will restart. It was raining the day it originally died so I think it is wiring harness related although it got a good tuneup in the process. The famous Dakota splice has been taken apart and redone as well. I'll try to keep you updated in case someone else should ever run into this! Time to walk away and think for now.......

[78clubcab]

Looks like I may finally have the problem fixed. A good friend an excellent mechanic did some diagnostics and it is looking like the main computer is shorting out. It is just killing everything, like ASD relay, fuel pump relay, ignition, all of it! New computer on the way!

[78clubcab]

OK, I know its been awhile, but truck is finally fixed! It turned out not to be the computer, but instead the cam position sensor. It has been running perfect for 2 months now. The cam sensor should have tripped the check engine light, but for some reason it shorted so badly it took the whole truck electrical system with it. A good friend and excellent SAE mechanic found this out by plugging in a diagnostic computer that at first said it was connected to the vehicle but could not read the computer. When the cam sensor was unplugged, the scan tool could read the computer, and the rest of the truck came to life by the fuel pump priming and ASD relay, and ignition relay all now had power. I just wanted to post this because after further research, the cam sensor's are known to do this on 1st generation trucks. Hope nthis can help someone!

[DODGEBOYS]

The 1987-2001 Chrysler vehicles .

Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. (On is *not* start!)
The "check engine" light will flash. Count the flashes Each code is a two digit code, so a (for example) 23 would be FLASH FLASH (pause) FLASH FLASH FLASH (loong pause)
It will never flash more than 9 times, watch for pauses!
55 is end of codes - it's normal. Before you call your dealer or mechanic, consider that the blink-spacing is not always perfectly uniform, so if you see 23 23, it's probably just a single 55. (Codes are not repeated.)
33 is normal on earlier models if you don't have air conditioning.
John McGuire wrote: "The older Vipers will blink out diag codes with four off/on key turns. They removed the capability starting in... I think 2000, at any rate I know my 2001 requires a computer to check the codes."
On some models (such as a 1995 Neon), when the check engine light goes on, you may be able to get the codes simply by putting in the key and moving it to the RUN position; the light will blink out the codes by itself.
Please note that some codes are NOT included below, this is not a complete listing, but it IS very close to complete. It stems from a list posted on the Mopar Mailing List, but many modifications have been made.
* Activates Power Limited/Check Engine light on some models.
IMPORTANT. Codes may be different for newer vehicles starting in the late 1990s. See the earlier section.

11 No ignition reference signal detected during cranking (bad Hall effect) OR timing belt skipped one or more teeth; OR loss of either camshaft or crankshaft position sensor. Can cause the engine to stop working entirely with no limp-home mode.
12 Battery or computer recently disconnected
13* MAP sensor or vacuum line may not be working
14* MAP sensor voltage below .16V or over 4.96V
15 No speed/distance sensor signal
16* Loss of battery voltage detected with engine running
17 Engine stays cool too long (bad thermostat or coolant sensor?)
17 (1985 turbo only): knock sensor circuit

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21 Oxygen sensor signal doesn't change (stays at 4.3-4.5V). Probably bad oxygen sensor
22* Coolant sensor signal out of range - May have been disconnected to set timing
23* Incoming air temperature sensor may be bad
24* Throttle position sensor over 4.96V (SEE NOTE #3)
25 Automatic Idle Speed (AIS) motor driver circuit shorted or target idle not reached, vacuum leak found
26 Peak injector circuit voltage has not been reached (need to check computer signals, voltage reg, injectors) (SEE NOTE #4 BELOW)
27 Injector circuit isn't switching when it's told to (TBI)
OR (MPI) injector circuit #1 not switching right
OR (turbo) injector circuit #2 not switching right
OR (all 1990-) injector output driver not responding
- check computer, connections


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31 Bad evaporator purge solenoid circuit or driver
32 (1984 only) power loss/limited lamp or circuit
32 EGR gases not working (1988) - check vacuum, valve
32 (1990-92, all but Turbo) computer didn't see change in air/'fuel ratio when EGR activated - check valve, vacuum lines, and EGR electrical
33 Air conditioning clutch relay circuit open or shorted (may be in the wide-open-throttle cutoff circuit)
34 (1984-86) EGR solenoid circuit shorted or open
34 (1987-1991) speed control shorted or open
35 Cooling fan relay circuit open or shorted
35 (trucks) idle switch motor fault - check connections
36 (turbo) Waste gate control circuit open or shorted
36 (3.9/5.2 RWD) solenoid coil circuit (air switching)
36 (Turbo IV) #3 Vent Solenoid open/short
37 Shift indicator light failure, 5-speed
OR
part throttle lock/unlock solenoid driver circuit (87-89)
OR
solenoid coil circuit (85-89 Turbo I-IV)
OR
Trans temperature sensor voltage low (1995 and on; see NOTE 2)


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41* Alternator field control circuit open or shorted
42 Automatic shutdown relay circuit open or shorted
42 Fuel pump relay control circuit
42 Fuel level unit - no change over miles
OR
42 Z1 voltage missing when auto shutdown[ASD] circuit energized (SEE NOTE #6)
43 Peak primary coil current not achieved with max dwell time
OR
43 Cylinder misfire
OR
43 Problem in power module to logic module interface
44 No FJ2 voltage present at logic board
OR
44 Logic module self-diagnostics indicate problem
OR
44 Battery temperature out of range (see Note #1!)
45 Turbo boost limit exceeded (engine was shut down by logic module)
46* Battery voltage too high during charging or charging system voltage too low
47 Battery voltage too low and alternator output too low


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51 Oxygen sensor stuck at lean position (Bob Lincoln wrote: may be tripped by a bad MAP sensor system causing a rich condition, and the O2 sensor trying to compensate. The O2 sensor may still be good. The MAP assembly consists of two pieces, the valve and the vacuum transducer (round plastic unit with cylinder on top and both electrical and vacuum connections) - If you get hot rough idle and stalling, especially on deceleration, accompanied by flooded engine and difficulty restarting, that can be a bad MAP sensor causing the O2 sensor to try to compensate. If you get poor cold drive ability, stumbling and bucking, and acceptable warm driving with poor gas mileage (a drop of 10 mpg or more), that is usually the O2 sensor. [Webmaster note: MAP sensors seem to die regularly.]
OR

51 Internal logic module fault ('84 turbo only).
52 Oxygen sensor stuck at rich position (SEE NOTE #5!)
OR
52 Internal logic module fault ('84 turbo only)
53 Logic module internal problem
54 No sync pickup signal during engine rotation (turbo only)
OR
54 Internal logic module fault ('84 turbo only) - or camshaft sensor/distributor timing (7)
55 End of codes


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61 "Baro" sensor open or shorted
62 EMR mileage cannot be stored in EEPROM
62 PCM failure SRI mile not stored
63 Controller cannot write to EEPROM
64 Catalytic converter efficiency failure
65 Power steering switch failure


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88 Start of test (not usually given, don't expect it)
Footnotes


NOTE #1.The power module has an air-cooled resistor which senses incoming air temperature. The logic modules uses this information to control the field current in the alternator. This code applies ONLY to alternators whose voltage is computer regulated. If you lose the feed to keep RAM information stored when the engine's off, you also lose battery voltage sensing. -- Bohdan Bodnar

NOTE #2.From the 1995 TRUCK manuals: the trailer towing package includes a transmission coolant temp sensor while the standard package doesn't. This may cause the low (no) voltage indication. -- J.E. Winburn

NOTE #3.Matt Rowe comments: The throttle postion circuit tells the computer how far the accelerator is depressed. The Throttle Position Sensor (TPS) is on the throttle body on the opposite side of the throttle cable. The connector should have a round rubber cover over the connections. Clear the fault codes, start the car and try jiggling the wires/connectors to try to trip a fault code. Loss of this signal could cause other problems.

NOTE #4.During cranking, the computer will test the current through the injector to see whether there's too much resistance in the injector's path. If there is, code 26 is set.

The problem may be cured with tuner cleaner on the connectors.

For TBI engines, the injector's cold resistance should be between 0.9 and 1.2 ohms (specs vary with year). This is a peak-and-hold injector. With the engine idling the peak period should be about 1.2 milliseconds whereas the hold period will vary. If it's lower than this at idle, then the injector's shorted or there's a defect in the injector driver circuit. (Bohdan Bodnar)

NOTE #5.Wade Goldman wrote: In my case, the breather tube leading into the catalytic converter had rusted and become detached. This some how would cause the sensor to read an over rich condition and run crummy. I did not trust the reliability of the weld over a corroded surface and opted for the more expensive route of replacing the converter, breather tube and all.

NOTE #6.The Z1 voltage is the voltage of the circuits fed by the auto shutdown relay. This typically includes fuel pump and switched-battery feed to the ignition coil(s). In my Le Baron, the Z1 circuit leaves the power module and splits into two paths: the fuel pump and the positive side of the ignition coil. Internal to the power module is the auto shutdown relay (in my case, it's a sealed box about 1" by 1"). The output voltage is monitored to determine whether the relay responds correctly. I suspect that the ASD relay (and, therefore, the Z1 circuit) also feeds the fuel injector(s) driver(s) and current sensing circuit, but can't prove this.

I've used the Z1 voltage to test for good power connections to the power module. I connected my OTC 500 multimeter from the battery's positive post to the ignition coil's switched battery terminal and measured the voltage drop using the bar graph to monitor peak voltages. Voltage spikes of around 200 mV to 300 mV are ok -- anything more means tv tuner cleaner time (or replacing the power module). Another thing to check is the maximum voltage drop during the priming pulse. With the old power module, I was losing about 2 volts across the circuit; the replacement is losing about 1/4 volt. (Thanks, bbodnar@lucent.com)

Note #7Steve Knickerbocker wrote: Inside your distributor you have two pickups, one is for the ignition and one is to tell the computer where number one cylinder is in its rotation. If you look at the four slotted tangs inside there you will see one has a bigger slot, that's the one that tells the sync pickup what's number one. In other words, the pickup inside the distributor is bad.

this is reprinted with permission