Cummins-Onan QG i error code 26 (QG i DF)
Alternator Undervoltage. Indicates that the inverter bus voltage 150V, the generator set will not shutdown but without output. DC rail (bus) voltage below 150V. AC output is cut, engine keeps running; restart to recover. Service causes: load too large, loose connector, low alternator output, low engine speed, inverter, alternator. QG i DF dual-fuel family (QG 7000i DF = HGLCA, QG 4000i DF = HGLDA, QG 2800i DF = HGLEA) code table - distinct from the QG 2800i/2500i (HGLAA) table and from the HGJAA (0983-0501) and KY tables. The status indicator flashes a 1-digit code, or two sets of flashes (tens, pause, units) for a 2-digit code; flashing stops after 5 minutes and pressing STOP/PRIME 3 times within 5 seconds resumes it. The last fault logged keeps flashing after the condition is corrected.
What to check, and in what order, is in the app. A step-by-step flow walks this code with the pass/fail measurements, wiring schematics and procedures that go with it, and it works offline in the bay.
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- Operator Manual RV Generator Set HGLCA Spec A (QG 7000i DF), A079E225 Issue 1Cummins Onan
- Operator Manual RV Generator Set HGLDA Spec A (QG 4000i DF), A080H582 Issue 1Cummins Onan
- Operator Manual RV Generator Set HGLEA Spec A (QG 2800i DF), A080H579 Issue 1Cummins Onan
- Service Manual RV Generator Set HGLCA Spec A (QG 7000i DF), A079E227 Issue 1Cummins Onan
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