P1312
Read the instructions below then
start the fault diagnostic procedure.
Symptom: CHECK ENGINE.
Combustion Detection Cyl. 1+2. Open Circuit / Short to B+.
Fault symptoms
On-Board Diagnostics
Type of diagnosis:
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Continuous. However, it is interrupted once the fault criteria have been fulfilled and does not restart until the next driving cycle.
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Enable criteria:
(Conditions that must be fulfilled for diagnostics to be performed.)
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Global conditions for this diagnostic trouble code: When starting the engine, the atmospheric pressure must exceed 78 kPa and the temperature of the coolant and the intake air must exceed -7°C.
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Engine running. Main relay voltage exceeding 10V. Ignition synchronized.
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Fault criteria:
(When enable criteria have been fulfilled, diagnostics will check if the fault criteria have been fulfilled.)
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Voltage constantly exceeding 5V for 200 combustions.
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Dependents:
(Once fault criteria have been fulfilled, a number of other diagnostics must report OK before the diagnostic trouble code can finally be generated.)
System reaction to a fault:
(Once the fault criteria have been fulfilled, certain measures will sometimes be taken.)
OK report:
(This diagnosis may be included as a dependent to another diagnosis and must therefore report OK even if it is continuous. The OK report is also used in fault handling to count down the fault counter.)
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Enable criteria fulfilled. Fault criteria for P1312 or P1334 not fulfilled within 300 combustions.
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Fault handling:
(Refer to section “Fault diagnosis, general” for more information.)
Diagnostic help
Fault diagnosis concerns an electrical fault in the connecting lead.
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Combustion signal cyl. 1+2/bank 1, unit %
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Check the wiring
Jiggle the wiring harness at several points and in different directions to check if there are intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostic instrument during the test.
