The computer codes are 121155. What does this mean?
Code retrieval can be accessed by the ignition key or by a diagnostic readout box(DRB).To obtain the codes using the key method,set the park brake,and put the vehicle in Park/neutral.
Some 95 and later OBDII vehicles, you may be able to retrieve OBDII codes with this procedure, if equipped with digital dash:
* Turn the ignition key ON,OFF,ON,OFF,and finally ON again(ENGINE NOT RUNNING)
* The codes will start to flash on the POWER LOSS or CHECK ENGINE light.
* FLASH,pause,FLASH,FLASH=code 12
The codes showed are...
Fault Code 12
Description: Memory standby power recently lost
Power loss light: Off
Limp-in mode: None
Possible Causes:* Battery or power line recently disconnected - This code is
normal if the electrical system has been worked on or the battery has
recently been disconnected. It will be removed after 15 ignition switch
on/off cycles.
* Low system voltage, bad battery or battery terminals - If the
system recently had a power drop (due to a dead battery or bad
alternator), this code will appear. If the battery terminals are bad
and the engine was jumped, this code will appear.
* Bad connection or wiring - Check the wiring and connections
between the battery, power module, and logic module (or SMEC). Check
all fusible links and power connectors to the battery. Clean and
regrease any corroded connectors with dielectric grease and repair any
shorts.
Diagnostic Method
Trigger Parameters
- Logic module receives power after previously not having power
Results If Component Fails
Fault code 12 is stored. The logic module is basically telling you
that it has lost power and will not remember any previously stored codes
or engine sensor table data. The code will be removed after 15
ignition on/off cycles and the logic module will use default values for
all look-up tables as a starting point until it "learns" the attributes
of the engine.
Fault Code 11
Description: Engine not cranked since last reset or no ignition reference signal detected during cranking
Power loss light: Off
Limp-in mode: None
Possible Causes:
* Engine hasn't been cranked since last reset - Power was removed from the logic module (disconnected or dead battery, etc.) and the logic module has no memory of seeing a signal from the ignition reference sensor. Crank the engine and check for the code again. If the logic module saw a signal, the code will be cleared. This code will not show up if the sensor simply fails. The logic module must be reset and the engine cranked to see if the sensor is working.
* Bad connection or wiring - Check the wiring and connections between the hall effect sensor (located underneath the distributer cap) and the logic module. Check the continuity of the two 3 conductor cables coming out of the sensor--these are prone to fatiguing and breaking inside the insulation where they exit the sensor if the cables are not properly tied down. You may be able to resolder them. Clean and regrease any corroded connectors with dielectric grease and repair any shorts. This code will not show up if the sensor simply fails. The logic module must be reset and the engine cranked to see if the sensor is working (see above).
* Hall effect sensor failure- Check the ignition reference sensor and fuel injector sync sensor cables. They are the two, flat 3 conductor cables coming out of the sensor at the base of the distributer cap. These often fatigue where they exit from the sensor. Upon replacing the sensor, make sure the cables are clipped or tied to the distributor cap shroud (or elsewhere) so they do not swing around. This code will not show up if the sensor simply fails. The logic module must be reset and the engine cranked to see if the sensor is working (see above).
Diagnostic Method
Trigger Parameters
- Computer has been reset
- No signal from the ignition reference sensor has been detected
Results If Component Fails
Fault code 11 is stored and the engine will not start (even if the ignition reference sensor is working). A running engine will stall, but no code will be stored. The logic module must be reset and the engine cranked to see if the sensor is working.
Fault Code 55
Description: End of message
Power loss light: Off
Limp-in mode: None
Possible Causes:
* No further fault codes are stored. If this is the only code received, then there are no codes stored in memory. This code will always be given, even if nothing is wrong. If you do not get this code, then you may not be retreiving the codes properly, or the power loss light may be burnt out. The light should come on for 1 second when the ignition is initally turned on as a bulb test.
Diagnostic Method
Trigger Parameters
- No further codes in memory
Hope helps (remember comment and rated this)
Thanks. Yes, battery and connections are good. I might have to take it to the dealership to see if their scanner can yield any insights. From reading other WCM is my best guess, but I'm definitely not a car expert.
Also to add:
-issue is apparently intermittent - won't crank/start this morning or after driving the car for a few minutes, but this afternoon tried to start several times and it was successful (until driven)
-can reset by disconnecting the battery
-when it doesn't start the engine light is on, but no engine codes from OB II reader or using the key sequence to display engine codes in the odometer
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