Mitsubishi P1AB8
CMU04 module temperature abnormal (low input), P1AB9: CMU05 module temperature abnormal (low input), P1ABA: CMU06 module temperature abnormal (low input), P1ABB: CMU07 module tempe
Quick answer
P1AB8 is identified for the CMU04 module as “module temperature abnormal (low input)” on applicable U.S.-market Mitsubishi i-MiEV vehicles. Official Mitsubishi TSB evidence describes a diagnostic process using the BMU special-function screen; if the DTC remains stored after that process, the specified resolution is replacement of the Main Drive Lithium-ion Battery.
This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.
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1. What does P1AB8 mean?
P1AB8 is identified for the CMU04 module as “module temperature abnormal (low input)” on applicable U.S.-market Mitsubishi i-MiEV vehicles. Official Mitsubishi TSB evidence describes a diagnostic process using the BMU special-function screen; if the DTC remains stored after that process, the specified resolution is replacement of the Main Drive Lithium-ion Battery.
2. Technical explanation
P1AB8 belongs to a group of battery-monitoring diagnostic codes. In the supplied official TSB evidence, P1AB8 specifically corresponds to “CMU04 module temperature abnormal (low input).” The same TSB lists neighboring codes for other CMU module positions, but this page concerns P1AB8 only. The supplied evidence does not establish a component-level root cause beyond the reported abnormal low temperature input condition.
3. What system is affected?
Main Drive Lithium-ion Battery / battery monitoring system (CMU04), as indicated by the official TSB diagnostic and repair direction.
4. How serious is this code?
Not yet established by verified evidence. The supplied record does not assign a severity level.
5. Symptoms you may notice
- A stored P1AB8 DTC is established by the supplied official TSB evidence.
- Other vehicle symptoms are not yet established by verified evidence.
6. Possible causes
- An abnormal low input reported for the CMU04 module temperature signal is established by the DTC definition.
- A specific underlying failure cause is not yet established by verified evidence.
7. Can I still drive the vehicle?
Not yet established by verified evidence.
8. Can I charge the vehicle?
Not yet established by verified evidence.
9. What you can safely do
- Arrange diagnosis by a qualified Mitsubishi EV service facility.
- Do not attempt high-voltage battery diagnosis, disassembly, or repair yourself.
10. Step-by-step troubleshooting
- Use the BMU special-function screen and execute the applicable procedure, as described in the official Mitsubishi TSB evidence.
- Check whether the diagnostic trouble code remains stored after the specified procedure.
- If P1AB8 remains stored, the TSB directs replacement of the Main Drive Lithium-ion Battery.
- If the code is not stored after the procedure, the TSB states that diagnosis is complete.
11. When to contact service
Service is appropriate because the official procedure involves BMU special-function diagnostics and may require Main Drive Lithium-ion Battery replacement. Use a qualified Mitsubishi EV service facility.
12. What the service center may check
- Retrieve and confirm P1AB8 using the BMU diagnostic process.
- Execute the applicable BMU special-function procedure referenced by the Mitsubishi TSB.
- Determine whether the DTC remains stored after that procedure.
- Replace the Main Drive Lithium-ion Battery if the DTC remains stored, according to the TSB.
13. Possible repair or resolution
- Per the official TSB evidence: if P1AB8 remains stored after the specified BMU special-function procedure, replace the Main Drive Lithium-ion Battery.
- Per the official TSB evidence: if the DTC is not stored after that procedure, the diagnosis is complete.
14. Affected vehicles
- Mitsubishi i-MiEV · 2012 · US
- Mitsubishi i-MiEV · 2014 · US
15. Related TSBs / service bulletins
- Mitsubishi TSB-19-54-004, published March 13, 2019; NHTSA manufacturer communication MC-10158409. It lists P1AB8 as “CMU04 module temperature abnormal (low input)” and provides the stored-code decision path leading to Main Drive Lithium-ion Battery replacement.
- Mitsubishi TSB-19-54-003, published March 13, 2019; NHTSA manufacturer communication MC-10158408. It lists P1AB8 as “CMU04 module temperature abnormal (low input)” and provides the same stored-code decision path.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified official sources: NHTSA-hosted Mitsubishi manufacturer communications TSB-19-54-004 (MC-10158409) and TSB-19-54-003 (MC-10158408), both published March 13, 2019. Applicability supplied for this diagnostic is 2012 and 2014 Mitsubishi i-MiEV vehicles in the United States.
19. Frequently asked questions
What does P1AB8 mean?
The official TSB evidence identifies P1AB8 as “CMU04 module temperature abnormal (low input).”
Which vehicles are covered by the supplied applicability data?
The supplied applicability data identifies U.S.-market 2012 and 2014 Mitsubishi i-MiEV vehicles.
What does the official TSB direct if P1AB8 remains stored?
After the specified BMU special-function procedure, the TSB directs replacement of the Main Drive Lithium-ion Battery if the DTC remains stored.
Is it safe to drive or charge with P1AB8?
Not yet established by verified evidence.