RF Engine

• Improper engine idling or engine fails to idle
  Cause: Intake system out of order — Clogged air cleaner element
  Fix: Clean or replace.
• Hard starting (Engine cranks OK)
  Cause: Engine and emission control system out of order — Faulty ECM
  Fix: Inspect and replace.
• Engine hesitates when accelerating
  Cause: Intake system out of order — Clogged air cleaner element
  Fix: Clean or replace.
• Overheating
  Cause: Insufficient coolant
  Fix: Replenish.
• Hunts while driving
  Cause: Fuel system out of order — Fuel filter: Dirty or clogged
  Fix: Replace.
• Abnormal knocking
  Cause: Fuel system out of order — Fuel injection pipe: Cracks
  Fix: Replace.
• TP sensor — Throttle opening is controlled as closed 32
• TCC solenoid valve — TCC solenoid valve OFF 25
• IAT sensor signal — High signal voltage; Open circuit; Low signal voltage 23
  Fix: Set intake air temp. to appropriate temp., and perform each control; IAT sensor; Related wiring harness
• VSS signal — No VSS signal input 24
  Fix: Detect vehicle speed as 0 km/h (or more), and perform each control; VSS; Related wiring harnesses
• Vehicle speed sensor (A/T) — Vehicle speed signal not inputted 31
  Cause: "W" or "O" wire open or poor coupler connection; Improper installation or faulty A/T vehicle speed sensor; Poor "A5" or "A19" terminal connection
  Fix: Check resistance between "A5" and "A19" terminal of disconnected TCM coupler (369-451 Ω); Check voltage between "A5" and "A19" terminal of TCM coupler when vehicle running at 40 km/h on lift (0.5-1.0 V by using AC voltmeter); If wire and connection are OK, replace A/T vehicle speed sensor; If connections are OK, substitute a known-good TCM and recheck
• Vehicle speed sensor (A/T) — Signal from vehicle speed sensor (Meter) is used 31
• Vehicle speed sensor (A/T) — Defective sensor or its circuit (open or short) 31
• Vehicle speed sensor (A/T and Meter) — Vehicle speed signal not inputted 36
  Cause: Faulty "BI/Y" wire or poor "A32" connection; "BI/B" or "B/Or" wire open or short; Malfunction of VSS drive or driven gear; Speedometer malfunction; "BI/Y" wire open/short or faulty TCM; Poor VSS connection or VSS malfunction
  Fix: Refer to item DTC-31 in this section; Check if speedometer indicates vehicle speed; Check voltage between "BI/B" wire terminal and "B/Or" wire terminal of VSS coupler (about 10-14 V); Check voltage between "BI/Y" and "B/Or" terminals of VSS coupler (4 V or more); Check VSS drive and driven gears for damage and excessive wear; Check voltage between "BI/Y" and "B/Or" terminals of VSS coupler (about 4-5 V); If wire and connection are OK, intermittent trouble or faulty TCM; If connection is OK, substitute a known-good VSS and recheck; If wire and connection are OK, substitute a known-good TCM and recheck
• Vehicle speed sensor (A/T and Meter) — Shift solenoid valve A and B is controlled as OFF 36

Compiled from service & troubleshooting documentation across every generator set that uses the RF.

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.