Code
P1693
CHRYSLER
P — Powertrain
DTC Detected In ECM Or PCM
Views:
UK: 23
EN: 61
RU: 100
AI status
Completed
Completed
100%
Causes
- Other DTCs stored in the ECM/PCM (root faults elsewhere)
- Intermittent or lost network communications (CAN, K-Line)
- Low or unstable battery/charging system voltage
- Poor ground or corroded connector at the PCM/ECM
- Internal PCM/ECM memory, software, or processor fault
- Recent battery disconnect, module reflash, or incomplete programming
Symptoms
- Malfunction Indicator Lamp (MIL) or other warning lamps illuminated
- One or more additional DTCs present when scanning vehicle
- Possible limp-home mode or reduced performance depending on underlying faults
- Intermittent loss of module communication on the diagnostic tool
- Stored freeze frame data related to another fault
What to check
- Read and save all current and history codes from the ECM/PCM and other modules (ABS, TCM, BCM).
- Record freeze frame and live-data PIDs for any related codes.
- Check battery resting voltage and voltage during cranking/starting (nominal ~12.4–12.7 V resting, ≥13.5 V with engine running).
- Inspect PCM/ECM power and ground connectors for corrosion, bent pins, or poor mating.
- Verify CAN bus continuity and voltage levels; look for shorts to power or ground.
- Check for intermittent communication using a scan tool while performing system operations or a scope for CAN signals.
Signal parameters
- Battery voltage (key ON and engine running)
- PCM/ECM supply and ground circuit voltages
- CAN High/Low voltages and differential waveform during operation (~2.5 V nominal per line, ~0 V to ±2.5 V differential pulses)
- Module response to OBD-II requests (presence/absence of ECUs)
- Number and type of stored DTCs returned from ECM/PCM
- Freeze frame parameters associated with other stored DTCs
Diagnostic algorithm
- Connect a factory-level or capable OBD-II scanner and record all codes from every module (ECM, TCM, ABS, BCM, etc.). Note freeze-frame and pending codes.
- Investigate and diagnose any other stored DTCs first — P1693 commonly appears because of those underlying faults.
- Clear all codes and perform a key cycle, then re-scan. If P1693 and others return immediately, proceed with power/communication checks.
- Test battery state-of-charge and charging system. Recharge or replace battery if voltage is low or failing.
- Visually inspect and back-probe PCM power and ground terminals; repair any damaged wiring or poor ground connections.
- Check CAN bus for shorts or open circuits; use an oscilloscope or diagnostic tool to confirm proper network activity and message traffic.
- If electrical and network systems are good but the code returns, check for known software updates/TSBs and consider reflashing the PCM per manufacturer procedure.
- If module internal faults are suspected after all wiring and software checks, consult factory diagnostics for guided PCM testing and consider module replacement only after thorough verification.
- After corrective actions, clear codes and road test to ensure faults do not reoccur.
Likely causes
- Persistent DTC(s) in another module (engine, transmission, ABS, etc.)
- Weak battery or charging system causing module resets
- Damaged or loose wiring to PCM/ECM power or ground circuits
- CAN bus wiring damage, short or high resistance connection
- Corroded or poorly seated PCM connector pins
- PCM firmware/software needing an update or reflash
Fault status
Status
ECM/PCM reports one or more diagnostic trouble codes detected in module memory or a module-level/internal/communication fault. Further diagnosis of stored codes and vehicle networks required.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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