New Holland WorkMaster 50 Service Manual page 990

Electrical systems - FAULT CODES
DTC 607-03-Lambda sensor O2 calibrator too high error
Control Module : ECU
NOTE: If the Lambda sensor B-9123 is replaced, it is necessary to perform the Replacement of the Lambda Sensor
- Reset ECU Data with the Electronic Service Tool (EST) before you return the machine to service. See Lambda
sensor - Configure - Reset ECU data (Lambda sensor) (55.989), if necessary.
Context:
The Engine Control Unit (ECU) A-9000 performs an electrical zero-offset calibration every 10 min of engine operation
on the Lambda sensor B-9123 as long as the engine has been running for longer than 10 s after start, after-treatment
regeneration is not active, the engine is in operating range one (speed between 300 - 1200 RPM and load between
2.00 - 11.00 mg per stroke), and the calibration is not inhibited due to a failure. The measured oxygen signal during
calibration should be between - 0.200 - 0.200 V. If the oxygen signal, during this calibration, is out of range, higher
than 0.200 V, this fault will occur. For more information regarding fuel system troubleshooting, see Fuel injection
system - Troubleshooting (10.218). For information regarding the functional operation of the Lambda sensor B-9123
see Lambda sensor - Overview (55.989). For more information regarding the technical specifications of the lambda
sensor B-9123, see Lambda sensor - Technical Data (55.989).
Cause:
The Lambda sensor B-9123 oxygen level signal, during calibration, to the ECU A-9000 is greater than 0.200 V.
Possible failure modes:
1. Faulty injector, leaking.
2. Faulty Exhaust Gas Recirculation (EGR) Z-9000 valve, stuck closed. (If applicable)
3. Faulty Lambda sensor B-9123, contaminated.
4. Faulty ECU A-9000, software.
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