P1923
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Some of the following symptoms may perhaps be observed:
Engine fails to start.
CHECK ENGINE.
Automatic transmission not shifting gear.
CHECK GEARBOX
Additional trouble codes in Trionic (P1624 or P1908).
Diagnostic trouble code P1921 or P1902 in TCM (if the TCM can be contacted).
No Bus Data From TCM. See Fault Tracing 3:5 Bus and Diagnostic Communication.
Fault symptoms
Some of the following symptoms may perhaps be observed:
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Automatic transmission not shifting gear.
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Additional trouble codes in Trionic (P1624 or P1908).
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Diagnostic trouble code P1921 or P1902 in TCM (if the TCM can be contacted).
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On-Board Diagnostics
Type of diagnosis:
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Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.
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Enable criteria:
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Engine running. TCM has previously been on the bus on some occasion.
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Fault criteria:
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No communication for more than 3 s.
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Dependents:
System reaction to a fault:
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Max. engine torque (Bus from TCM) set to 310 Nm.
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OK report:
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Enable criteria fulfilled and fault criteria not fulfilled within 60 s.
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Fault handling:
(See section
Fault handling III, other emission-related components and functions
for more information.)
Diagnostic help
Fault diagnosis concerns intermittent electrical faults in the power supply for the sending control module or in a bus lead.
Check the wiring
Jiggle the leads and in-line connectors at various points and in different directions to detect any intermittent breaks or short circuits in the wiring. Observe the multimeter, test lamp or diagnostic tool while doing this.
