P1A99 Code - Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current
Quick Answer
The purpose of the Accessory Power Module (APM), integral to the Starter/Generator Control Module (SGCM), is to control the amount and direction of energy flowing between the 42 volts DC and 14 volts DC buses via the APM, bi-directional 42 volts DC to 14 volts DC converter. Common causes include Faulty Starter/Generator Control Module (SGCM), Starter/Generator Control Module (SGCM) harness is open or shorted, Starter/Generator Control Module (SGCM) circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1A99 indicates Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current.
- Common causes
- Common causes include Faulty Starter/Generator Control Module (SGCM), Starter/Generator Control Module (SGCM) harness is open or shorted, Starter/Generator Control Module (SGCM) circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1A99 Description
The Starter/Generator Control Module (SGCM) controls 2 functions in these DTCs. DC voltage is transformed into three phase AC power to the electric machine interface. In this case, energy flows from 36 volt to phase1, phase2 and phase3. The second case shall be generating, where the three phase AC power is used to charge the 36 volt battery pack. In this case, energy flows from phase1, phase2 and phase3 to 36 volts.
What are the Possible Causes of the DTC P1A99?
- Faulty Starter/Generator Control Module (SGCM)
- Starter/Generator Control Module (SGCM) harness is open or shorted
- Starter/Generator Control Module (SGCM) circuit poor electrical connection
How to Fix the DTC P1A99?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1A99 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- P1A99 Buick — Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current
- P1A99 Cadillac — Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current
- P1A99 Chevrolet — Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current
- P1A99 GMC — Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current
- P1A99 Saturn — Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current
Frequently Asked Questions about P1A99 Code
1. What are common symptoms of OBDII code P1A99?
Common symptoms of code P1A99 may include a malfunction indicator light (MIL) on the dashboard, reduced hybrid system performance, or difficulty starting the vehicle.
2. What can cause the Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current code?
Possible causes of code P1A99 include a faulty hybrid battery current sensor, damaged wiring or connectors in the circuit, or issues with the starter/generator control module.
3. How can I diagnose the Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current issue?
Diagnosing code P1A99 typically involves using a scan tool to retrieve the fault code, testing the hybrid battery current sensor, inspecting the wiring and connectors for damage, and checking the starter/generator control module.
4. Can I still drive my vehicle with OBDII code P1A99 present?
It is not recommended to drive your vehicle with an active P1A99 fault code, as it can lead to further damage to the hybrid system. It is best to address the issue promptly.
5. Are there any DIY repair tips for resolving the Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current fault?
DIY repair tips for P1A99 may include checking and cleaning the connectors in the circuit, testing the hybrid battery current sensor for proper function, and inspecting the wiring for any visible damage.
6. Is it necessary to replace the hybrid battery if OBDII code P1A99 appears?
Not necessarily. While the hybrid battery could be a potential cause of the issue, it is recommended to diagnose the specific component causing the fault before considering a battery replacement.
7. How much does it typically cost to repair OBDII code P1A99?
The cost of repairing code P1A99 can vary depending on the exact cause of the issue, labor rates in your area, and whether any components need to be replaced. It's best to consult a professional for an accurate estimate.
8. Can a faulty hybrid battery current sensor be repaired, or does it need to be replaced?
In most cases, a faulty hybrid battery current sensor will need to be replaced rather than repaired. It is a critical component of the hybrid system and is essential for accurate monitoring of current flow.
9. Will resetting the fault code make OBDII code P1A99 go away permanently?
Resetting the fault code may temporarily clear the MIL, but if the underlying issue causing code P1A99 is not addressed, the code is likely to reappear. It's important to diagnose and repair the problem to prevent recurrence.
10. How long does it take to repair the Starter/Generator Control Module Hybrid Battery Current Sensor Circuit Low Current issue?
The repair time for code P1A99 can vary depending on the complexity of the diagnosis and the extent of the repair needed. It's best to consult a mechanic for a more accurate estimate of the repair timeline.
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