I've got some pretty bad shaking in reverse, almost as if one cylinder is dead. I've also got an 0102 CEL, ignition signal circuit. Any idea how to fix / troubleshoot/diagnose this? I've tried new coilpacks but that didn't help.

 

Turn car on, pull E-Brake, but car in reverse....start pulling coil pack wires. See if a cylinder is misfiring. At this point, you can tell if a specific cyl is misfiring, whether it be an injector, coil or ....hmm.

Noticed, when I had a misfire...it would consistently misfire in reverse at idle...not consistent when in Drive.

 

0102
Diagnostic Trouble Code 0102 points to a problem with the Mass Air Flow Sensor. The MAFS is placed in the stream of intake air. It measures the intake flow rate by measuring a part of the entire intake flow. It consists of a thin film that is supplied with electric current from the Engine Control Module. The temperature of the hot film is controlled by the ECM a certain amount. The heat generated by the hot wire is reduced as the intake air flows around it. The more air, the greater the heat loss. Therefore, the ECM must supply more electric current to the hot film as air flow increases. This maintains the temperature of the hot film. The ECM detects the air flow by means of this current change.

This malfunction is detected when an out-of-range voltage is sent to the ECM. That voltage might be too high or too low.

a) An excessively high voltage from the MAFS is sent when the engine is not running.
b) An excessively high voltage from the MAFS is sent under light load driving conditions.

Possible causes include...
- Harness or connectors (the sensor circuit is open or shorted.)
- Faulty MAFS

c) An excessively low voltage from the MAFS is sent when the engine is not running.
d) An excessively low voltage from the MAFS is sent under heavy load driving conditions.

Possible causes include...
- Harness or connectors (the sensor circuit is open or shorted.)
- Intake air leaks
- Faulty MAFS

With DTC 0102 the ECM is supposed to switch into Fail Safe mode and limit engine speed to 2400 rpm.

unless you meant this
0201
Diagnostic Trouble Code 0201 indicates a problem with the ignition coil and power transistor. The ignition signal from the Engine Control Module is sent to and amplified by the power transistor. The power transistor turns on and off the ignition coil primary circuit. This on-off operation induces the proper high voltage in the coil secondary circuit.

The malfunction is detected when the ignition signal in the primary circuit is not entered during engine cranking or running.

The items to check include
- Harness or connectors (the ignition primary circuit is open or shorted.)
- Power transistor unit built into ignition coil
- Condenser
- Crankshaft Position Sensor (REF)
- Crankshaft Position Sensor (REF) circuit

A misfire on any individual cylinder should set a code, and a problem with the CPS should also set a code.

I would have expected to see DTC 0201 along with one of the following DTCs.
0407 - Crankshaft Position Sensor (REF)
0608 - Cylinder 1 misfire
0607 - Cylinder 2 misfire
0606 - Cylinder 3 misfire
0605 - Cylinder 4 misfire
0604 - Cylinder 5 misfire
0603 - Cylinder 6 misfire

You didn't get one of these "companion" DTCs, and that is puzzling. Maybe one of them will show up in the next few days.

 

yeah it was the second one. definately no other codes along with this one, its been like this for a while now. not sure what the next step is??

 

Don't read hte Injector stuff since we know it's a coil prob.

0603 0604 0605 0606 0607 0608
If one cylinder is misfiring the problem is spark or fuel. A misfire due to a spark problem usually results in a Service Engine Soon light and one of these Diagnostic Trouble Codes:
0608 - Cylinder 1 misfire
0607 - Cylinder 2 misfire
0606 - Cylinder 3 misfire
0605 - Cylinder 4 misfire
0604 - Cylinder 5 misfire
0603 - Cylinder 6 misfire

There are two tests the home mechanic can make, the sound test and the resistance test.

Sound test...
This test is performed with the engine idling. Use a mechanic's
stethoscope or a length of rubber vacuum hose, and listen to each injector.
All injectors should sound alike. If you find one which makes a different
sound (or no sound at all) you have found a problem.

Resistance test...
This test is performed with the engine off. Use an ohmmeter to measure the
resistance of each injector. This does not require removing the injectors.
I don't know the correct resistance value for the injectors on your model,
but they are typically a low number such as 16 ohms. The important thing
is they should all be equal. If you find one injector with substantially
higher resistance than the others, it is bad. If you find one with zero
ohms (short circuit) that is truly unfortunate, because the injector is bad
and it may also have damaged the Engine Control Module (the computer)
because of excessive current drain.

Measuring the resistance of the front bank of cylinders is easy because the
injectors are in plain view. Disconnect the injector electrical connector
for cylinder #2, measure the resistance, reconnect the connector. Repeat
for the cylinders #4 and #6.

Measuring the resistance of the rear bank of cylinders is almost as easy,
but it is difficult to reach the injectors. The resistance may be measured
at a conveniently located electrical connector. Notice the largest,
thickest electrical harness at the top of the engine. This is the Engine
Control Harness and it is shaped like a U, with the open top of the U at the
driver's side of the car. The U has two corners. Look at the corner
nearest the passenger seat. Just inside that corner you will find an 8-pin
electrical connector. This is connector F131. Disconnect this
connector. Now look at the male part, the connector half with the pins
exposed. They are arranged in two rows of four pins.
The pins are numbered 1 - 4 (top row) and 5 - 8 (bottom row).
Measure the resistance of:
- injector #1 between pins 1 and 2.
- injector #3 between pins 1 and 6.
- injector #5 between pins 1 and 5.
Be sure to measure the PINS, not the female receptacles.

The dealer's shop is equipped with high-tech diagnostic instruments. These are wonderful devices but they are expensive and the dealer has to recover his cost by charging you for diagnostic time. Sometimes the home mechanic can do legitimate diagnostic work with nothing more than a ohmmeter and a rubber tube.

To Test Ignition Coils:
With the ignition off, disconnect the electrical connector from the ignition coil. Connect the positive (+) probe of an ohmmeter to terminal no. 1 and the negative (-) probe to terminal no. 2 of the coil connector - the meter should indicate infinite resistance. Reverse the meter leads ( negative probe to terminal no. 1 and positive probe to terminal no.2) - the continuity should be indicated, but not zero ohms. If the results are not as specified, replace the coil.
Connect an ohmmeter between the secondary terminal ( the one that the spark plug connects to) and terminal no. 1 - the meter should indicate infinite resistance. If not, replace the coil.
Note - Ohm meter to test coils is not the most reliable way. Some peoples’ coils tested perfectly, but they still misfired.

 

Will try this tommorow and report back what I've found, thanks for all the info !

Quick question , When I measure resitance, do I put one end of the meter to gorund and the other any one of the connections in the injector/coil pack?

 

You gotta find the cyl that is misfiring first. So pull coil pack wires while car is running in reverse first ...and see which cyl is misfiring. Only do this if the car is misfiring consistently at idle. Basically, when you pull the coil pack wires, and the car runs the same (just as rough), you found the right cyl to focus on.

If you do find the cyl that is misfiring then:

Swap coil pack from good cyl to bad cyl, and see if the misfire follows the bad coil pack. If not then,

testing coil packs is useless. So don't bother. Replace Coil pack with OEM one.

If the misfire doesn't follow the "bad" coil pack, then testing injectors is useful. Test between the leads as mentioned above. If you have resistance of 11-14 ohms, this is good. If it's dead, it'll read infinite resistance.

Anything else, and ur wasting time and money.