P1693

Code

PONTIAC P — Powertrain

DTC Detected In ECM Or PCM

Brand: PONTIAC

Type: P — Powertrain

Views: UK: 20 EN: 43 RU: 86

AI status

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Page language: EN

Causes

Stored DTC(s) in the ECM/PCM memory
Intermittent or persistent loss of power or ground to the ECM/PCM
Module internal fault or corrupted calibration/memory
CAN/serial communication errors between modules
Poor connector pins, corrosion, or damaged wiring
Incorrect or incomplete reprogramming or software mismatch

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
One or more drivability issues (stalling, poor idle, hesitation) depending on underlying code
Unable to clear codes or codes return immediately after clearing
Loss of certain functions controlled by the PCM/ECM
Multiple modules report communication errors on the scan tool

What to check

Perform a full OEM-level scan of all modules; read stored, pending and permanent codes and freeze frame data
Verify battery voltage (engine off and cranking) and charging system operation
Inspect ECM/PCM connectors for corrosion, bent pins, pushed-out terminals or water intrusion
Verify power and ground circuits to the ECM/PCM with a wiring diagram and DVOM
Check CAN/high-speed data bus for shorts to power/ground and proper termination
Look up technical service bulletins (TSBs) or software updates related to the vehicle and P1693

Signal parameters

Battery voltage (key on, engine off and while cranking) — expect near 12.4–12.8 V (KOEO) and >9–10 V cranking
PCM supply voltage and ignition feed (verify presence when key ON)
PCM ground circuit voltage drop during cranking and at rest
CAN bus voltages (CAN High ~2.5–3.5 V, CAN Low ~1.5–1.8 V) and bus activity with scan tool
Module awake/sleep status and message counters from scan tool
OBD monitors status and readiness, presence of other U-codes (communication faults)

Diagnostic algorithm

Connect an OEM-capable scan tool and retrieve all codes from all modules; document code numbers, freeze frame and PID data.
Note whether P1693 is accompanied by other specific P- or U-codes; those codes usually identify the subsystem to focus on.
Verify battery and charging system health. Recharge or replace battery if voltage is low; retest.
Visually inspect ECM/PCM connectors and wiring. Repair any damaged wiring or corroded terminals found.
Check ECM/PCM power and ground circuits for proper voltage and minimal resistance to battery ground.
Test CAN/network continuity and for shorts. Repair any wiring faults and verify proper termination resistances.
Clear codes and perform a road or drive cycle to see if P1693 (or associated codes) returns. If it does, capture freeze frame and PIDs at failure.
If communication or internal module faults persist, check service information for reprogramming or calibration updates; perform reflash if required.
Only after confirming wiring, power/ground and software are good, consider module replacement. Program/configure replacement module per OEM procedures.
Re-scan all modules after repair and confirm readiness monitors and that codes do not return.

Likely causes

Loose, corroded, or disconnected ECM/PCM power or ground circuit
Failed ECM/PCM hardware (processor, memory)
Network communication fault (CAN bus short/open/high resistance)
Recent module replacement not configured/programmed correctly
Stored internal DTC(s) triggered by a separate subsystem fault

Fault status

⚠️ Status

DTC Detected In ECM Or PCM — the ECM/PCM reports a diagnostic trouble code was logged. Further scanning of the ECM/PCM and other modules is required to identify the specific underlying fault.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3 hours

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P1693 — DTC Detected In ECM Or PCM