SPN 1172/FMI 4
This code is typically sensor or circuit failed low.
Check as follows:
- Turn the ignition OFF.
- Disconnect the TCI Sensor.
- Disconnect the 120–pin MCM connector.
- Measure resistance between pin 1 and pin 2 of the TCI Sensor Harness connector.
- If the resistance is less than 3 Ω, repair the short between pin 1 and pin 2 of the TCI Sensor Harness connector and pin86 and pin 88 of the 120–pin MCM connector. Refer to “82.3.1 Verify Repairs” .
- If the resistance is greater than 3 Ω, repair the short to ground between pin 2 of the TCI Sensor and pin 86 of the 120–pin MCM connector. Refer to “82.3.1 Verify Repairs” .
Verify repairs as follows:
- Turn ignition OFF.
- Reconnect any electrical connections that were disconnected to perform the diagnosis.
- Clear codes with DDDL 7.0 or latest version.
ENGINE EXHAUST To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.
- Start and bring engine up to operating temperature (over 140°F/60°C).
- Verify operation is satisfactory and no warning lamps illuminate. If warning lamps illuminate, troubleshoot the codes.