some code help needed
#1
01-03-2008, 05:28 PM
some code help needed
Well, i got over my obsession quickly of customizing my blazer, i have returned it all to stock, took off the drop kit, put the factory rims and factory tuned ecm back on. the truck is completly back to stock except for the flowmaster muffler. all was well till the weather got cold and it threw a SES code. i put the scanner on it and it comes up with P1345 - random ignition misfire. The truck seems to run smoothly and has all normal power. the code stayed off till i restarted the truck and the code came up again. When i had the custom tuned ecm on, it had the ses light on constantly because i never did a case learn as instructed by jesse bubb, however i took that ecm back off and put the stock one back in and now i have the code mentioned above, any ideas as to what could be causing this? i did my last tune up in 2005 when the fuel pump went bad and that consisted of plugs, wires, cap and rotor. any help greatly appreciated, i need to get a nys inspection and can not with the ses light on or a code stored.
help....!!!
help....!!!
#2
01-03-2008, 06:12 PM
RE: some code help needed
Um... P1345 == Crankshaft Position (CKP) - Camshaft Position (CMP) Correlation...
This is usually indicative of a vehicle that has either had a CKP replacement, CMP replacement, or a PCM replacement. All three of which will require a Crankshaft Variation Learn Procedure which can only be done with a Tech2 or compatible scan tool.
This is usually indicative of a vehicle that has either had a CKP replacement, CMP replacement, or a PCM replacement. All three of which will require a Crankshaft Variation Learn Procedure which can only be done with a Tech2 or compatible scan tool.
#3
01-03-2008, 06:22 PM
RE: some code help needed
thanks for the quick response... the pcm was replaced, i took the stock one out for a custom tuned one, then replaced custom tuned one with the stocker, so i guess it has to be taken to a shop for a case learn eventhough i am using the stock pcm again. any ideas on how hard to find a shop or someone with that type of scanner or do i need a dealer? any idea if this will prevent a nys inspection from going thru now that it is all computerized?
#4
01-03-2008, 06:26 PM
RE: some code help needed
I'm not sure if this code will cause it to fail a NYS inspection...
One other possibility that I just read up on is that the CKP sensor may be dirty, but if it wasn't a problem before with the other PCM, then I'm not sure why it would have a problem now... Maybe something to check before getting the CASE learn done.
About the case learn, I can perform it with my AutoEnginuity scanner and I know that many other higher feature scan tools can also do this. You would just have to ask around using both CASE learn & Crankshaft Variation Learn procedure in your conversations as many places call it different things.
One other possibility that I just read up on is that the CKP sensor may be dirty, but if it wasn't a problem before with the other PCM, then I'm not sure why it would have a problem now... Maybe something to check before getting the CASE learn done.
About the case learn, I can perform it with my AutoEnginuity scanner and I know that many other higher feature scan tools can also do this. You would just have to ask around using both CASE learn & Crankshaft Variation Learn procedure in your conversations as many places call it different things.
#6
01-03-2008, 07:21 PM
RE: some code help needed
Well heck, if you were going to go all the way to Rochester, you could just swing by my place...
Circuit Diagram:
Diagnostic Trouble Chart (table):
My scan tool can do everything except the DTC specific tests that are referenced on the chart...
Circuit Diagram:
CIRCUIT DESCRIPTION
This Diagnostic Trouble Code (DTC) monitors the Crankshaft Position (CKP) and the Camshaft Position (CMP) signals to determine if they are synchronized. If both signals are not observed by the control module within a narrow time window, the Vehicle Control Module (VCM) will determine that an error has occurred.
CONDITIONS FOR RUNNING THE DTC
The engine is running.
CONDITIONS FOR SETTING THE DTC
When the engine is running, the cam sensor reference pulse is not detected at the correct position relative to the crankshaft position sensor pulse.
ACTION TAKEN WHEN THE DTC SETS
* The control module illuminates the Malfunction Indicator Lamp (MIL) if a failure is detected during 2 consecutive key cycles.
* The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame and Failure Records.
CONDITIONS FOR CLEARING THE MIL OR DTC
* The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.
* A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.
* Use a scan tool in order to clear the DTCs.
DIAGNOSTIC AIDS
Check the following items:
A loose CMP sensor causing a variance in the sensor signal.
* Excessive free play in the timing chain and gear assembly.
* Incorrectly installed distributor - 1 tooth off in either advance or retard positions.
* A loose distributor rotor on the distributor shaft.
* A loose or missing distributor hold down bolt.
An intermittent may be caused by any of the following conditions:
* A poor connection
* Rubbed through wire insulation
* A broken wire inside the insulation
Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for intermittent and Poor Connections in Diagrams.
If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Diagrams.
TEST DESCRIPTION
The numbers below refer to the step numbers on the table.
4. This test will determine if this DTC is intermittent.
5. If there is a variance in the camshaft sensor signal it will be detected in this step.
6. Unintentional damage to the distributor shaft may result if excessive pressure is used to rotate the distributor.
This Diagnostic Trouble Code (DTC) monitors the Crankshaft Position (CKP) and the Camshaft Position (CMP) signals to determine if they are synchronized. If both signals are not observed by the control module within a narrow time window, the Vehicle Control Module (VCM) will determine that an error has occurred.
CONDITIONS FOR RUNNING THE DTC
The engine is running.
CONDITIONS FOR SETTING THE DTC
When the engine is running, the cam sensor reference pulse is not detected at the correct position relative to the crankshaft position sensor pulse.
ACTION TAKEN WHEN THE DTC SETS
* The control module illuminates the Malfunction Indicator Lamp (MIL) if a failure is detected during 2 consecutive key cycles.
* The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame and Failure Records.
CONDITIONS FOR CLEARING THE MIL OR DTC
* The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.
* A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.
* Use a scan tool in order to clear the DTCs.
DIAGNOSTIC AIDS
Check the following items:
A loose CMP sensor causing a variance in the sensor signal.
* Excessive free play in the timing chain and gear assembly.
* Incorrectly installed distributor - 1 tooth off in either advance or retard positions.
* A loose distributor rotor on the distributor shaft.
* A loose or missing distributor hold down bolt.
An intermittent may be caused by any of the following conditions:
* A poor connection
* Rubbed through wire insulation
* A broken wire inside the insulation
Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for intermittent and Poor Connections in Diagrams.
If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Diagrams.
TEST DESCRIPTION
The numbers below refer to the step numbers on the table.
4. This test will determine if this DTC is intermittent.
5. If there is a variance in the camshaft sensor signal it will be detected in this step.
6. Unintentional damage to the distributor shaft may result if excessive pressure is used to rotate the distributor.
My scan tool can do everything except the DTC specific tests that are referenced on the chart...
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