NOTE: Barometric sensor is built into ECM. Circuit testing is not required.

Turn ignition off. Remove BACK-UP fuse (7.5-amp) from underhood fuse/relay box for 10 seconds to reset ECM. Check ECM for fault codes. If Code 13 is not present, problem is intermittent. Check for poor connections at ECM connector and Transmission Control Module (TCM) connector (if equipped). Test drive vehicle and check again.
If Code 13 is present on M/T models, go to step 4. If Code 13 is present on A/T models, turn ignition off. Connect ECM Test Harness (07LAJ-PT3010A ) to ECM, leaving ECM wiring harness disconnected. See Figure . Disconnect 18-pin connector from TCM. Check for continuity between test terminal D8 and body ground.
If continuity is present, repair short in Red/White wire between ECM connector terminal D8 and TCM. If continuity is not present, substitute a known good TCM. If MIL goes off and Code 13 is not present, replace original TCM. If MIL stays on and/or Code 13 is still present, go to next step.
Replace ECM and retest.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Code 13: Barometric (BARO) Sensor