Case IH 1805 – ISM-IDI: ISM-IDI High DOC Intake temperature

The exhaust gas temperature entering the Diesel Oxidation Catalyst (DOC) has exceeded the maximum safe operational limit. This condition can be triggered by a faulty temperature sensor reading artificially high, a restriction in the exhaust/aftertreatment system, or an engine over-fueling issue (such as leaking injectors) that is driving up exhaust temperatures.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR series
• SV series
• TR series
• TV series
• SR160B
• SR175

1. 1

   Check for related electrical codes (1800 or 1801) which indicate a circuit issue rather than an actual overheating event.

2. 2

   Inspect the wiring harness and connector leading to the DOC intake temperature sensor for melting, chafing, or corrosion.

3. 3

   Monitor live data using the Case IH Electronic Service Tool (EST). If the sensor reports an impossibly high temperature while the exhaust is physically cold, the sensor is internally shorted.

4. 4

   If the sensor reads accurately, inspect the engine for over-fueling conditions (e.g., leaking injectors) and check the DPF and DOC for heavy soot restrictions.

1. 1

   Cool Down

   Ensure the machine is turned off and the exhaust system has completely cooled down. The DOC and surrounding aftertreatment components operate at extremely high temperatures and pose a severe burn risk.

2. 2

   Locate the Sensor

   Locate the DOC intake temperature sensor. It is threaded into the exhaust pipe just before the Diesel Oxidation Catalyst (DOC) inlet, typically the first sensor downstream of the turbocharger and exhaust manifold.

3. 3

   Disconnect the Harness

   Carefully unclip and disconnect the electrical pigtail harness from the sensor.

4. 4

   Remove the Sensor

   Using a wrench or a specialized sensor socket, loosen and remove the temperature sensor from the exhaust housing.

5. 5

   Install the New Sensor

   Apply a small amount of high-temperature anti-seize to the threads of the new sensor (if it does not come pre-applied). Thread the sensor in by hand to prevent cross-threading, then tighten it securely to OEM specifications.

6. 6

   Reconnect

   Plug the electrical connector back into the machine's wiring harness until the locking tab clicks.

7. 7

   Clear Codes

   Turn the ignition on and use the Case IH EST diagnostic tool to clear the 1805 fault code. Start the engine and monitor the exhaust temperatures to verify the repair is successful.