JLG Scissor Lift 32 Fault Code: Charge Air Temperature Warning
Also called Contactor Did Not Open When De-energized, Heated Oxygen Sensor (HO2S) Low Voltage, Indicates That a Contactor Did Not Open When De-Energized - Contactor Driver Permanently On, Indicates That a Contactor Did Not Open When De-Energized - Line Contactor Miswired On or Welded
Charge Air Temperature Warning · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Fault code 32 on JLG scissor lifts (SPN 105 / FMI 0) most commonly points to the power module's line contactor failing to open when it should be de-energized, or in some engine variants, a charge air temperature warning. On the electrical side, drive, steer, and lift up functions are prevented until the fault clears.
High severity. Drive, steer, and lift up are locked out when this fault is active on the contactor variant, which stops the machine from being used until the issue is found. The welded or stuck-on contactor condition can also involve a power wiring error, so treat it as a stop-and-diagnose situation rather than something to work around.
What does JLG Scissor Lift error code 32 mean?
>This fault code covers more than one condition depending on the machine and controller, but on JLG scissor lifts the dominant meaning is an electrical fault in the power module's line contactor circuit. The line contactor is the switch that connects and disconnects battery power to the drive system. If it fails to open when the controller tells it to de-energize, the machine cannot safely confirm that power is disconnected, so it locks out drive, steer, and lift up as a precaution.
There are two closely related versions of this cause. In one, the contactor driver circuitry itself failed its power-up self-test and stayed permanently on, reported by the power module as a separate internal code (14d for driver-on, or 23d depending on which self-test failed). In the other, the drive circuitry passed its self-test but the actual line contactor did not open when commanded, which the power module reports as a 'contactor welded' condition. A related description ties this to the capacitor bank charge not decreasing from battery supply when the contactor was de-energized, which can point to a power wiring error.
A separate, unrelated description under the same code number is a charge air temperature warning on certain engine-equipped models. This is a functional warning that charge air temperature has exceeded a warning level, and it clears on its own once the temperature drops back below a recovery level, subject to a delay for time-fill limitation. Which meaning applies to your machine depends on the engine or controller installed, so check your CANbus power module message and status documentation to confirm.
Common causes of 32
- Line contactor drive circuitry failed to de-energize during power-up self-tests (contactor driver reported permanently on).
- Line contactor drive circuitry passed self-tests, but the physical line contactor did not open when de-energized (reported as contactor welded).
- Power wiring error causing the capacitor bank charge to not decrease from battery supply when the line contactor was de-energized.
- On engine-equipped variants, charge air temperature exceeded its warning level, often linked to a faulty charge air temperature sensor or cable.
How to troubleshoot JLG Scissor Lift 32: first checks
- >Check the CANbus power module message and status data for the specific internal fault code (14d or 23d) to confirm whether the issue is a driver-on condition or a welded contactor.
- Inspect line contactor wiring for signs of a power wiring error, including reversed or miswired connections that could keep the contactor engaged.
- Visually and physically inspect the line contactor itself for signs of welding, pitting, or sticking contacts.
- On engine-equipped machines, check the charge air system and the charge air temperature sensor and its cable for damage, corrosion, or loose connections.
- Confirm battery supply voltage and capacitor bank behavior when the contactor is commanded to de-energize, looking for charge that fails to decrease as expected.
How the code clears
No separate clearing step is listed for the contactor version of this fault beyond correcting the underlying wiring or contactor issue and referring to the CANbus power module documentation for status. For the charge air temperature warning version, the fault message clears on its own once charge air temperature drops back below the recovery level, subject to a delay for time-fill limitation.
Frequently asked questions
What does JLG fault code 32 mean?
It usually means the power module detected that the line contactor did not open when it was supposed to de-energize, which can be due to a stuck driver circuit or a welded contactor. On some engine-equipped scissor lifts, the same code number is also used for a charge air temperature warning, so check your machine's documentation to know which applies.
Why won't my JLG scissor lift drive, steer, or lift up with code 32 active?
When the line contactor fails to open as commanded, the controller cannot verify that power is safely disconnected, so it disables drive, steer, and lift up as a protective measure until the fault is resolved.
Is a welded contactor dangerous?
Yes. A welded or stuck-closed line contactor means power may stay connected to the drive system even when the controller thinks it has cut power. This is why JLG locks out major functions until the condition is corrected.
Can a wiring error cause this fault?
Yes. One listed cause is a power wiring error that prevents the capacitor bank charge from decreasing from battery supply when the line contactor is de-energized. This should be checked alongside the contactor itself.
Does code 32 ever clear itself?
On the charge air temperature warning version, yes, it clears automatically once the temperature drops below the recovery level after a delay. On the contactor version, no separate reset is listed, so the underlying wiring or contactor problem must be fixed first.
What should I check first if I get code 32?
Start by pulling the CANbus power module status data to see if it reports a specific internal code such as 14d or 23d, then inspect the line contactor and its wiring for welding, sticking, or miswiring before assuming a sensor issue.
Is this the same as a charge air temperature fault?
Not always. Code 32 is shared across multiple fault descriptions depending on the machine's configuration. On engine-equipped units it can represent a charge air temperature warning, while on others it represents the line contactor issue. Confirm which one is active on your specific machine before diagnosing.