P1C64 on Ram
On Ram 1500 eTorque trucks, the hybrid system saw the engine turn slower than its target when stop-start tried to restart it
Severity: Inspect soon
FCA's bulletins describe an autostart that fails and leaves the transmission in limp mode, and owners report stalling in traffic, so book a dealer visit soon rather than ignoring it.
It gets more serious if:
- Stop: Stop driving and call for help if the truck stalls, will not restart, or the battery light comes on; FCA describes a stall and loss of 12 V charging with the motor generator unit fault, and owners report stalling in traffic.
This page covers only what differs on Ram. For what P1C64 means, the ranked causes and the test order, see the P1C64 guide.
What's different on Ram
RamYour car
2019–2022 · 1500
Supported by vehicle dataSoftware updates for 2022 trucks and an MGU connector bulletin for 2020-2021 trucks name P1C64. Whether the bulletins are still current is not verified.
08-093-22Status unverified
HCP software update for P1C64 autostart failure
20221500 · issued · NHTSA 10214603
P1C64 and U0402 with an autostart that fails and the transmission in limp mode: update the hybrid control processor software.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
08-025-23Status unverified
HCP software update, P1C64 and U0402
20221500 · issued · NHTSA 10231802
Same concern and remedy as 08-093-22: P1C64 with U0402, autostart failing and AutoPark engaging; reflash the HCP.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
08-014-21Status unverified
MGU connector not fully seated
2020–20211500 · issued · NHTSA 10187133
P1C64 with U0594, P1B03, P0A3F, P0607 or P0A92, a stall 15-40 minutes into driving and no restart: replace the motor generator unit.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
9004484Status unverified
Document before replacing the MGU for noise or P1C64
2019–20221500 · issued · NHTSA 10214520
Dealers should create a scan report and call engineering before replacing an MGU for whining noise or P1C64.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Sources and review
- FCA 08-093-22: Flash: Hybrid Control Processor (HCP) Updates
- FCA 08-025-23: Flash: Hybrid Control Processor (HCP) Updates
- FCA 08-014-21: Motor Generator Unit (MGU) Connector Not Fully Seated
- FCA 9004484: Motor Generator Unit
- NHTSA complaint 11438272: 2021 Ram 1500
- NHTSA complaint 11462915: 2021 Ram 1500
- NHTSA complaint 11633592: 2022 Ram 1500
- NHTSA complaint 11660434: 2022 Ram 1500
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error